A proton of mass m and charge +e is moving in a circular orbit in a magnetic field with energy 1 Me V. What should be the energy of α − particle (mass = 4m and charge = + 2e), so that it can revolve in the path of same radius?
A proton and an α-particle are projected in a uniform field in a direction perpendicular to the field. If the particles move in circular paths of same radius, then the ratio of linear momentum of proton to that of α-particle is
A proton moving with velocity v is acted upon by electric field E and magnetic field B The proton will move undeflected if
A proton of energy 8 e V is moving in a circular path in a uniform magnetic field. The energy of an alpha particle moving in the same magnetic field and along the same path will be
The figure shows a current carrying loop. Then select the correct option.
A uniformly charged rod with charge Q and length L is rotating about one end with constant angular speed ω . Find the magnetic dipole moment of the rod. Consider the mass of it is M.
A charged particle moves in a uniform magnetic field. The velocity of the particle at some instant makes an acute angle with the magnetic field. The path of the particle will be
An electron and a proton have equal kinetic energies. They enter in a magnetic field perpendicularly. Then
Consider a solenoid with 0.3 T magnetic field inside it. 8 cm long wire placed inside the solenoid perpendicular Find the magnetic force acting on a to its axis if the wire carry 10 A current:
Magnetic induction at the centre of a circular loop of area π square meter is 0.1 tesla. The magnetic moment of the loop is ( μ 0 is permeability of air)
Currents of 10A, 2A are passed through two parallel wires A and B respectively in opposite directions. If the wire A is infinitely long and the length of the wire B is 2 meter, the force on the conductor B, which is situated at 10 cm distance from A will be
A straight conductor carrying current i splits into two parts as shown in the figure. The radius of the circular loop is R. The total magnetic field at the centre P of the loop is,
An electron moves in a circular orbit with a uniform speed v. It produces a magnetic field Bat the centre of the circle. The radius of the circle is proportional to :
A voltmeter of resistance 1000 Ω gives full scale deflection when a current of 100 mA flows through it. The shunt resistance required across it to enable it to be used as an ammeter reading 1 A at fulI scale deflection, is
A galvanometer gives full scale deflection of 1 volt when acting like a voltmeter when connected in series with 2 k Ω resistance. The same galvanomeler gives 500 mA, fuIl scale deflection when acting like an ammeter when connected with shunt resistance of value 0.2 Ω in parallel. Find out the resistance of galvanometer.
A charged particle enters a uniform magnetic field with velocity vector at an angle of 45° with the magnetic field. The pitch of the helical path followed by the particle is p. The radius of the helix will be
A particle with charge q, moving with a momentum p, enters a uniform magnetic field normally. The magnetic field has magnitude B and is confined to a region of width d, where d < p Bq . If the particle is deflected by an angle θ in crossing the field, then
In a certain region of space, there exists a uniform and constant electric field of strength E along x-axis and uniform constant magnetic field of induction B along z-axis. A charged particle having charge q and mass m is projected with speed v parallel to x-axis from a point (a, b, 0). When the particle reaches a point 2 a , b 2 , 0 its speed becomes 2v. Find the value of electric field strength.
The charge on a particle Y is double the charge on particle X. These two particles X and Y after being accelerated through the same potential difference enter a region of uniform magnetic field and describe circular paths of radii R 1 and R 2 , respectively. The ratio of the mass of X to that of Y is
Mixed He + and O 2+ ions (mass of He + = 4 amu and that of O 2+ = 16 amu) beam passes a region of constant perpendicular magnetic field. If kinetic energies of all the ions are the same, then
A current of 10 A is flowing in a wire of length 1.5 m. A force of 15 N acts on it when it is placed in a uniform magnetic field of 2 T. The angle between the magnetic field and the direction of the current is
In the figure, a positively charged small sphere of mass m and the charge q starts sliding from rest on a vertical fixed circular smooth track of radius R from the position A shown. There exist a uniform magnetic field of B. Find the maximum force exerted by track on the sphere during its motion.
A square loop ABCD of side a carrying current I is folded about an axis passing through its centre (y-axis). The two halves are inclined at angle 30 0 with xy plane as shown. -Find the magnetic fieid at origin. The origin coincides with the centre of loop.
A particle of charge per unit mass α is released from origin with velocity v = v 0 i ^ in a magnetic field B = − B 0 k ^ for x ≤ 3 2 v 0 B 0 α and B = 0 for x > 3 2 v 0 B 0 α The x-coordinates of the particle at time t > π 3 B 0 α would be
An infinite wire bent in the form of I carries current i. What is the magnetic field at the point O ?
current r is flowing in a straight conductor of length l. The magnetic induction at a point distant l /4 from its centre will be(fig)
A wire carrying current I has the shape as shown in adjoining figure. Linear parts of the wire are very long and parallel to X -axis while semicircular portion of radius R is lying in Y-Z plane. Magnetic field at point O is
A long wire carrying a steady current is bent into a circular loop of one turn. The magnetic field at the centre of the loop is B. It is then bent into a circular coil of n turns. The magnetic field at the centre of this coil of n turns will be
A circular coil of radius R carries an electric current. The magnetic field due to the coil at a point on the axis of the coil located at a distance r from the centre of the coil, such that r >> R, varies as
In a hydrogen atom, magnetic field produced by the electron at the centre of circular orbit is ‘B’ when the atom is in ground state. What will be the magnetic field produced by the electron at the centre of circular orbit when the atom is in second excital state?
The magnetic field in a region is given by B = B 0 i ^ . A charged particle of specific charge α is given a velocity v = v 0 2 i ^ + 3 v 0 2 j ^ at the origin. Find the minimum distance of the point on the x-axis from the origin where the particle will cut the x-axis.
Two concentric coils, each of radius equal to 2 π cm, are placed at right angles to each other. Currents of 3A and 4 A, respectively, are flowing through the two coils. The magnetic induction, in Wb m – 2 , at the center of the coils will be [ μ 0 = 4 π × 10-7 Wb(A m – 1 )]
A solenoid has core of a material with relative permeability 500 and it carries a current of 1A. The number of turns of the solenoid is 500 per metre. The intensity of magnetization of the material is nearly
A current I flows along the length of an infinitely long straight thin walled pipe. Then
A galvanometer has a resistance of 25 Ω and a maximum of 0.01 A current can be passed through it. In order to change it into an arnmeter of range 10 A, the shunt resistance required is
A B C is a current carrying conductor carrying a current i = 2A. If length of the segment Ab is 3 3 m, then what should be the length of BC . So that net force on the conductor ABC becomes zero?
one end A of a current carrying wire AB, carrying a current of 2A, lies at the origin and the other end B lies at the point (3, 4) m. A uniform magnetic field B = 2 i ^ + j ^ + k ^ T exists in that region of space. Then force experienced by the wire AB is
To convert a 800 mV range milli voltmeter of resistance 40 Ω into a galvanometer of 100 mA range, the resistance to be connected as shunt is
In the circuit shown in figure. The ring is made of a wire of uniform cross-sectional area. If magnetic induction at the centre O produced by the segment ACB is 25µT, what will be the magnetic induction at O produced by the segment ADB ?
ABCD is a current carrying square loop. P is a point lying to the plane of the loop as shown in the figure. Then magnetic induction at P is
The magnetic induction at O due to the given arrangement where the ring is of radius r is
An ammeter reads up to 1 ampere. Its internal resistance is 0.81 ohm. To increase the range to 10 A, the value of the required shunt is
Four long insulated current carrying wires, cross each other as shown in the figure. If the separation between any pair of parallel wires is d, the magnetic induction at O is
A conductor, in the form of a right angle ∠ A B C with AB = 3 cm and BC = 4 cm, carries a current of 10 A. There is a uniform magnetic field of 5 T perpendicular to the plane of the conductor. The force on the conductor will be
Statement 1: A proton and an alpha particle having the same kinetic energy are moving in circular paths in a uniform magnetic field. The radii of their circular paths will be equal. Statement 2: Any two charged particles having equal kinetic energies and entering a region of uniform magnetic field B in a direction perpendicular to B , will describe circular trajectories of equal radii.
A proton moving with a constant velocity passes through a region of space without any change in its velocity. If E and B represent the electric and magnetic fields, respectively, then this region of space may have i E = 0 , B = 0 ii E = 0 , B ≠ 0 iii E ≠ 0 , B = 0 iv E ≠ 0 , B ≠ 0
Sensitivity of a moving coil galvanometer can be increased
A circular loop of radius P, carrying current i’ lies in x-y plane with its centre at origin The total magnetic flux through x-Y Plane is
An electron of mass m e initially at rest’ moves through a certain distance in a uniform electric field in time t 1 . R proton of mass m p , also, initially at rest’ takes time t 2 , to move through an equal distance in this uniform electric field. Neglecting the effect of gravity the ratio of t 2 / t 1 , is nearly equal to
Figure shows a coil of radius 2 cm concentric with a coil of radius 7 cm. Each coil has 1000 turns’ With a current of 5 amp in larger coil, find the current needed in the smaller coil to give the total magnetic field at the centre equal to 2 mT
A galvanometer, having a resistance of 50 Ω gives a full scale deflection for a current of 0.05 A. The length in metre of a resistance wire of area of cross-section 2.97x 10 -2 cm 2 that can be used to convert the galvanometer into an ammeter which can read a maximum of 5 A current is (specific resistance of wire = 5 x 10 -7 Ω m)
A uniform electric field and a uniform magnetic field are acting along the same direction in a certain region. If an electron is projected along the direction of the fields with a certain velocity, then
The magnetic field at the centre of a circular coil of radius r and carrying a current i is B. What is the magnetic field at a distance X = 3 r r from the centre, on the axis of the coil ?
A long straight wire of radius a carries a steady current I The current is uniformly distributed over its cross-section. The ratio of the magnetic fields B and B ‘ , at radial distances a 2 and 2 a respectively, from the axis of the wire is
A long solenoid has 1000 turns. When a current of 4 A flows through it, the magnetic flux linked with each turn of the solenoid is 4 × 10 – 3 Wb . The self-inductance of the solenoid is
A cylindrical conductor of radius R is carrying a constant current. The plot of the magnitude of the magnetic field, B with the distance, d from the centre of the conductor, is correctly represented by the figure
A current loop in a magnetic field
A long straight wire carries a certain current and produces a magnetic field 2 × 10 – 4 Weber m 2 at a perpendicular distance of 5 cm from the wire. An electron situated at 5 cm from the wire moves with a velocity 10 7 m / s towards the wire along perpendicular to it. The force experienced by the electron will be (charge on electron 1 . 6 × 10 – 19 C )
A 250 -turn rectangular coil of length 2.1 cm and width 1.25 cm carries a current of 85 μ A and subjected to a magnetic field of strength 0.85 T. Work done for rotating the coil by 180° against the torque is
A beam of electrons is accelerated though a potential difference V. It is then passed normally through a uniform magnetic field where it moves in a circle of radius r. It would have moved in a circle of radius 2r, if it were initially accelerated through a potential difference of
In a nuclear experiment a 1 Mev proton moves in a uniform magnetic field in a circular path of a certain radius.The energy of a deuteron which will circulate in the same orbit in the same magnetic field will be
A particle is moving with velocity v = i ^ + 3 j ^ and it produces an electric field at a point given by E = 2 k ^ . It will produce magnetic field at that point equal to (all quantities are in SI units)
A proton and an α -particle enter a uniform magnetic field moving with the same speed. If the proton takes 25 μ s to make 5 revolutions, then the periodic time for the α -particle would be
A circular coil of radius 4 cm has 50 turns. In this coil a current of 2 A is flowing. It is placed in a magnetic field of 0.1 weber/ m 2 . The amount of work done in rotating it through 180° from its equilibrium position will be
When a galvanometer is shunted with a 6 ohm resistance, the deflection is reduced to one third. If the galvanometer is further shunted with a resistance of 3 ohm, the deflection is reduced to (relative to first reading)
Dimensional formula of magnetic induction (B) is
Magnetic induction at a distance ‘r’ from the axis of a very long current carrying straight wire is B 1 . Now the wire is bent to form a circular loop of radius ‘r’ as shown in figure. The magnetic induction at the centre of the circular loop is found to be B 2 . Then B 1 B 2 is equal to
An α − p a r t i c l e and a proton are moving in circular paths in the same uniform magnetic field with same kinetic energy. Then the ratio of magnetic moment due to the rotation of α − p a r t i c l e to that of proton is
A very long straight cylindrical conductor of radius ‘a’ is carrying a steady current. If magnetic induction at the surface of a conductor is B 0 , what is the magnetic induction at a radial distance r = a 2 ?
A 0.1 m long conductor carrying a current of 50A is perpendicular to a magnetic field of 1.25mT. The mechanical power to move the conductor with a speed of 1 m/s in a direction perpendicular to its length and perpendicular to its length and perpendicular to the magnetic field is,
A proton and an α-particle after being accelerated through the same potential difference enter a region of uniform magnetic field and describe circular paths of radii R p and R α Then R p : R α is equal to
A current carrying wire is bent in the form of a circular ring and its magnetic dipole moment is found to be M. Now the same wire is bent in the form of a circular ring having two turns. Then new magnetic moment will be
A very long cylindrical conductor carries a current I. ‘p’ is point lying outside the conductor at a distance x from the surface of the conductor and magnetic induction at P is ‘B’. Then which of the following graphs correctly shows the variation of B with x?
Which of the following particles will have minimum frequency of revolution when projected with the same velocity perpendicular to a magnetic field ?
Two long straight parallel wires P and Q are kept at a separation of 1 m. Current in P is 3A and that in Q is 1A. Then distance of the point from P where the magnetic induction will be zoro is
A very long cylindrical wire of radius R carries a current I 0 uniformly distributed across the cross-section of the wire. Calculate the magnetic flux through a rectangle that has one side of length w running down the centre of the wire and another side of length R, as shown in figure.
An α − particle and a deutron enter a uniform magnetic field with same kinetic energy in a direction perpendicular to the direction of magnetic field. Then ratio of the radii of their paths r α : r d will be
Two long parallel wires are kept at a separation r . Magnitude of magnetic force experienced by unit length of each wire is F. If the separation between the wire is halved and current in each wire is doubled, then magnitude of force experienced by each wire will be
Resistance of a galvanometer coil is 100 Ω and permissible current through its coil is 10 mA. If can be converted into an ammeter of range 1A by connecting a resistance of
In a galvanometer, there is deflection of 5 divisions per μ A current. The resistance of galvanometers is 40 ohm. If shunt of 2 ohm is connected and if there are 50 divisions all over the scale of galvanometer, then the maximum current that can be measured by it is
Two similar coils of radius R are lying concentrically with their planes at angles to each other. The currents flowing in them are I and 2l respectively. The resultant magnetic field induction at the centre will be :
An ammeter gives full deflection when a current of 2 A flows through it. The resistance of ammeter is 12 Ω . If the same ammeter is to be used for measuring a maximum current of 5 A, then the ammeter must be connected with a resistance of
The core of a toroid having 3000 turns has inner and outer radii of 11 cm and 12 cm respectively. The magnetic flux density in the core for a current of 0.70 A is 2.5 T. What is the relative permeability of the core?
The resistance of a galvanometer is 50 Ω and the current required to give full scale deflection is 100 μ A . In order to convert it into an ammeter, reading upto 10 A, it is necessary to put a resistance of
A proton is projected from the origin making an angle of 60° with the x-axis. A magnetic field B = 2 i ^ tesla exists in that region of space. The proton passes through the x-axis for the first time at a distance of 50 cm from the origin. When an α – particle is projected from the origin with same speed making an angle of 30° with the x-axis in the same magnetic field, it passes though the x-axis at a distance ‘d’ from the origin. Then the value of ‘d’ is
A charged particle is moving in a gravity free space in a uniform magnetic field. If an on instant of time velocity vector is V = 16 i ^ – 4 j ^ m / s and acceleration vector is a = i ^ – b j ^ m / s 2 then magnitude of acceleration at that instant is
In a region of space both electric and magnetic fields exist. A charge particle is fired in that field and it passes unaccelerated. Then
When a proton is accelerated in a cyclotron device, maximum energy attained by it is 10 MeV. If radius of ‘Dee’ of the cyclotron is doubled and the magnetic field is doubled, then the maximum energy of on α-particle when accelerated in the cyclotron will be
A charged particle carrying a charge +Q is fixed at point 0, A uniform magnetic field of induction B exists in the region which points out of the plane of the page. An electron is projected from point P with velocity V as shown in the figure. Then path of the electron
Two ends of a current carrying wire AB of length l, radius r and resistivity of material ρ are connected to the terminals of a battery of emf E. The wire AB is placed in a uniform magnetic field of induction B as shown. Force experienced by the wire is 20 N. It radius of the wire is doubled and length also doubled, force experienced by the wire will be
A straight conductor of length 2m is carrying a current of 10 A. P is a paint at a distance of 2 3 m from end A as shown in figure. then magnetic induction at P is
In the arrangement shown, magnetic induction at the centre O is
A galvanometer of 50 ohm resistance has 25 divisions. A current of 4 × 10 – 4 ampere gives a deflection of one division. To convert this galvanometer into a voltmeter having a range of 25 volts, it should be connected with a resistance of
A potential difference of 600 volt is applied across the plates of a parallel plate capacitor, where plates are being separated by 3 mm. An electron projected vertically upward, parallel to the plates, with a velocity of 2 × 10 6 ms − 1 moves undeflected between the plates. The magnitude of the magnetic field in the region between the condenser plates is
A proton of mass 1 .67 × 10 − 27 kg and charge 1 .6 × 10 − 19 C is projected with a speed of 2 × 10 6 m / s at an angle of 60° to the X-axis. If a uniform magnetic field of 0.104 T is applied along Y-axis, the path of proton is
Current sensitivity of a moving coil galvanometer is 5 div/mA and its voltage sensitivity (angular deflection per unit voltage applied) is 20 div/V. The resistance of the galvanometer is
A proton and an alpha particle are separately projected in a region where a uniform magnetic field exists. Their initial velocities are perpendicular to direction of magnetic field. If both the particles move in magnetic field in circles of equal radii, the ratio of momentum of proton to alpha particle p p p α is
Maximum kinetic energy of the positive ion in the cyclotron is ( r 0 = R a d i u s o f c y c l o t r o n , q = c h a r g e o f i o n , m = m a s s o f i o n )
A proton and an electron, both moving with the same velocity v, enter into a region of magnetic field directed perpendicular to the velocity of the particles. They will now move in circular orbits such that
An electron mass = 9 .1 × 10 − 31 kg , charge = 1 .6 × 10 − 19 C experiences no deflection if subjected to an electric field of 3 .2 × 10 5 V / m and a magnetic fields of 0 . 2 μ T Both the fields are normal to the path of electron and to each other. If the electric field is removed, then the electron will revolve in an orbit of radius
An α − particle and a proton are both simultaneously projected in opposite directions into a region of constant magnetic field perpendicular to the direction of the field. After some time it is found that the velocity of the α − particle has changed in direction by 45°. Then at this time, the angle between velocity vectors of α − particle and proton is
A particle of charge per unit mass α is released from origin with a velocity v = v 0 i ^ in a uniform magnetic field B = − B 0 k ^ . If the particle passes through (0, y, 0), then y is equal to
For a positively charged particle, moving in an x-y plane initially along the x-axis, there is a sudden change in its path due to the presence of electric and/or magnetic fields beyond P. The curved path is shown in the x-y plane and is found to be non-circular. Which one of the following combinations is possible?
A particle of charge q and mass m moves in a circular orbit of radius r with angular speed ω . The ratio of the magnitude of its magnetic moment to that of its angular momentum depends on
If a charged particle of charge to mass ratio α enters in a magnetic field of strength B at a speed v = 2 αd B , then
A uniform magnetic field exists in region which forms an equilateral triangle of side a.· The magnetic field is perpendicular to the plane of the triangle. A charge q enters into this magnetic field perpendicular to a side with speed v. The charge enters from mid-point and leaves the field from mid-point of other side. Magnetic induction in the triangle is
The electric field acts along positive x-axis. A charged particle of charge q and mass m is released from origin and moves with velocity v = v 0 j ^ under the action of electric field and magnetic field, B = B 0 i ^ The velocity of particle becomes 2 v 0 after time 3 mv 0 2 qE 0 . Find the electric field.
Figure shows an equilateral triangle ABC of side l carrying currents as shown, and placed in a uniform magnetic field B perpendicular to the plane of triangle. The magnitude of magnetic force on triangle is
A particle of charge − 16 × 10 − 18 C moving with velocity 10 m s − 1 along x-axis enters a region where a magnetic field of induction B exists along the y-axis and an electric field of magnitude 10 4 V/m exists along the negative z-axis. If the charged particle continues moving along the x-axis, the magnitude of B is
Two thin, long, parallel wires, separated by a distance d carry a current of i ampere in the same direction. They will
Three long, straight and parallel wires carrying currents are arranged as shown in the figure. The wire C which carries a current of5.0A is so placed that it experiences no force. The distance of wire C from wire D is x centimetre. Then x is.
Two particles X and Y having equal charges, after being accelerated through the same potential difference, enter a region of uniform magnetic field and describes circular path of radius R 1 and R 2 , respectively. The ratio of mass of X to that of Y is
The loop ABCDEFGH, shown in figure, is carries a current i. A uniform magnetic field B exists in that region of space as shown in figure. Then magnetic torque experienced by the loop is, [Given, AB = BC = CD =l and EF = FG = GH = l/2]
A galvanometer, having a resistance of 50 Ω , gives a full scale deflection for a current of 0.05 A. The length in metre of a resistance wire of area of cross-section 2 .97 × 10 − 2 cm 2 that can be used to convert the galvanometer into an ammeter which can read a maximum of 5 A current is (Specific resistance of the wire = 5 × 10 − 7 Ω m )
The ammeter has range 1 ampere without shunt. The range can be varied by using different shunt resistances. The graph between shunt resistance and range will have the nature
In a gravity free space a charged particle is projected. If the kinetic energy of the particle changes and it also suffers deviation, then in that region of space
Two similar coils are kept mutually perpendicular such that their centres coincide. At the centre, find the ratio of the magnetic field due to one coil and the resultant magnetic field by both coils, if the same current is flown.
What will be the resultant magnetic field at origin due to four infinite length wires if each wire produces magnetic field B at origin?
In a mass spectrometer used for measuring the masses of ions, the ions are initially accelerated by an electric potential V and then made to describe semicircular paths of radius R using a magnetic field B. If V and B are kept constant, the ratio charge on the ion mass of the ion will be proportional to
In the given figure, net magnetic field at O will be
The coercivity of a bar magnet is 120 A/m. It is to be demagnetised by placing it inside a solenoid of length 120 cm and number of tums 72. The current flowing through the solenoid is
A current carrying coil is placed with its axis parallel to N-S direction. Let horizontal component of earth’s magnetic field be H 0 and magnetic field inside the loop is H. If a magnet is suspended inside the loop, it makes angle θ with H. Then θ is equal to
A particle of charge q and mass m moves in a circular orbit of radius r with angular speed Ï. The ratio of the magnitude of its magnetic moment to that of its angular momentum depends on
In fig. what is the magnetic field induction at point o
If a copper rod carries a direct current, the magnetic field associated with the current will be
The field B at the centre of a circular coil of radius -r is π times that due to a long straight wire at a distance r from it, for equal currents. Fig. shows three cases in all cases the circular part has radius r and straight ones are infinitely long. For same current the field B at the centre P in cases 1, 2, 3 has the ratio
Two long parallel wires are at a distance 2 d apart’ they carry steady equal currents flowing out of the plane of the paper as shown The variation of the magnetic field Belong the line XX’ is given by
Two long parallel wires are at a distance 2 d apart’ they carry steady equal currents flowing out of the plane of the paper as shown The variation of the magnetic field Belong the line XX’ is given by
The ratio of magnetic induction on the axis of a circular current carrying coil of radius r to the magnetic induction at its centre will be
A particle carrying a charge equal to 100 times the charge on an electron is rotating per second in a circular path of radius 0.8 m. The value of the magnetic field produced at the center will be ( μ 0 = permeability constant)
A galvanometer has a current range of 15 m A and a voltage range of 750 mV. To convert this galvanometer into ammeter of range 25 amp the shunt required is
A proton of mass m and charge +e is moving in a circular orbit of a magnetic field with energy 1 MeV. What should be the energy of α -particle (mass 4 m and charge + 2 e) so that it can revolve in the path of same radius
A uniform magnetic field acts right angles to the. direction of motion of electrons. As a result, the electron moves in a circular path of radius 2 cm. If the speed of electrons is doubled, then the radius of the circular path will be
Two thin long parallel wires separated by a distance d carry a current i amp in the same direction. They will
Two electrons move parallel to each other with equal speed v. The ratio of magnetic and electrical forces between them is
A 10 eV electron is circulating in a plane at right angles to a uniform field of magnetic induction 10 -4 Wb/m 2 (= 1.0 gauss), the orbital radius of electron is
A uniform electric field and a uniform magnetic field acting along the same direction in a certain region. If an electron is projected along the direction of the fields with a certain velocity, then
The radius of the circular path or helical path followed by the test charge q o moving in magnetic field B with some velocity v is
A charged particle enters a uniform magnetic field with a velocity vector at an angle 45 0 with the magnetic field. The pitch of the helical path followed by the particle is p , the radius of the helix will be
A proton of energy 8eV is moving in a circular path in a uniform magnetic field. The energy of an α – particle moving in the same magnetic field and along the same path will be-
A metal wire of mass m slides without friction on two rails spaced at a distance d apart. The track lies in a vertical uniform magnetic field B. A constant current I flows along one rail, across the wire and back down the other rail. If the wire is initially at rest, the time taken by it to move through a distance x along the track is
A thin circular wire carrying a current I has a magnetic moment M. The shape of the wire is changed to a square and it carries the same current. It will have a magnetic moment
Two identical coaxial circular loops carry current i each circulating in the clockwise direction. If the loops are approaching each other, then
Current sensitivity of a moving coil galvanometer is 5 div/mA and its voltage sensitivity (angular deflection per unit voltage applied) is 20 div/V. The resistance of the galvanometer is
A charged particle is released from rest in a region of steady uniform electric and magnetic fields which are parallel to each other. The particle will move in a
A circular coil of radius 4 cm has 50 turns. In this coil a current of 2 A is flowing. It is placed in a magnetic field of 0.1 weber / m 2 . The amount of work done in rotating it through 180° from its equilibrium position will be
In an ammeter 0.2% of main current passes through the galvanometer. If resistance of galvanometer is G, the resistance of ammeter will be
Two identical long conducting wires AOB and COD are placed at right angle to each other, with one above other such that 0 is their common point for the two. The wires carry I 1 a n d I 2 currents, respectively. Point P is lying at distance d from 0 along a direction perpendicular to the plane containing the wires. The magnetic field at the point P will be
A galvanometer of resistance 50 Ω is connected to a battery of 3 V along with a resistance of 2950 Ω in series. A full scale deflection of 30 divisions is obtained in the galvanometer. In order to reduce this deflection to 20 divisions, the resistance in series should be
A square loop ABCD carrying a current i,is placed near and coplanar with a long straight conductor XY carrying a current I, the net force on the loop will be
A charged particle(charge q) is moving in a circle of radius R with uniform speed ν . The associated magnetic moment μ is given by:
A toroid has a core of inner radius 25 cm and outer radius 26 cm around which 3500 turns of wire are wound. If the current in the wire is 11 A the magnetic induction out side the toroid in tesla.
A 2 MeV proton is moving perpendicular to a uniform magnetic field of 2.5 T. The force on the proton is
Ionized hydrogen atoms and α -particles with same momenta enters perpendicular to a constant magnetic field, B. The ratio of their radii of their paths r H : r α will be
A proton and an alpha particle both enter a region of uniform magnetic field B, moving at right angles to the field B. If the radius of circular orbits for both the particles is equal and the kinetic energy acquired by proton is 1 MeV, the energy acquired by the alpha particle will be
Work done on an electron moving in a solenoid along its axis is equal to :
A rectangular coil of length 0.12 m and width 0.1m having 50 turns of wire is suspended vertically in a uniform magnetic field of strength 0.2 Weber/ m 2 . The coil carries a current of 2 A. If the plane of the coil is inclined at an angle of 30° with the direction of the field, the torque required to keep the coil in stable equilibrium will be
Magnetic field at the centre of hydrogen like atom due to motion of electron in the n th orbit is proportional to
Magnetic field at the center of a circular coil is B. If area of the coil is A then magnetic moment of the loop is
A circuit contains an ammeter, a battery of 30 V and a resistance 40.8 ohm all connected in series. If the ammeter has a coil of resistance 480 ohm and a shunt of 20 ohm, the reading in the ammeter will be
When a proton is released from rest in a room, it starts with an initial acceleration a 0 towards west. When it is projected towards north with a speed υ 0 it moves with an initial acceleration 3 a 0 toward west. The electric and magnetic fields in the room are
A rectangular loop carrying a current ‘i’ is situated near a long straight wire such that the wire is parallel to one of the sides of the loop and is in the plane of the loop. If steady current I is established in the wire as shown in figure, the loop will
A small block of mass m, having charge q, is placed on a frictionless fixed inclined plane making an angle θ with the horizontal. There exists a uniform magnetic field B parallel to the inclined plane but perpendicular to the length of spring. If m is slightly pulled on the incline in downward direction and released, then the time period of oscillations of the block will be (assume that the block does not leave contact with the plane)
A circular loop of radius R carrying current I lies in x-y plane with its centre at origin. The total magnetic flux through x-y plane is
An electron moving in a circular orbit of radius r makes n rotations per second. The magnetic field produced at the centre has magnitude
An electron is moving in a circular path under the influence of a transverse magnetic field of 3 . 57 × 10 – 2 T. If the value of e / m is 1 . 76 × 10 11 C k g – 1 , the frequency of revolution of the electron is
A 2 MeV proton is moving perpendicular to a uniform magnetic field of 2.5 T. The force on the proton is
A circular coil ABCD carrying a current ‘i’ is placed in a uniform magnetic field. If the magnetic force on the segment A B is F , the force on the remaining segment BCDA is
Charge q is uniformly spread on a thin ring of radius R. The ring rotates about its axis with a uniform frequency f Hz. The magnitude of magnetic induction at the centre of the ring is :
A proton of velocity 3 i ^ + 2 j ^ m s − 1 enters a field of magnetic induction 2 j ^ + 3 k ^ tesla. The acceleration produced in the proton is (charge to mass ratio of proton = 0 . 96 × 10 8 C k g – 1 )
A solenoid 1.5 m long and 0.4 cm in diameter possesses 10 turns per cm length. A current of 5 A pass through it. The magnetic field at the axis inside the solenoid is :
An arrangement of three parallel straight wires placed perpendicular to plane of paper carrying same current ‘I’ along the same direction as shown in figure. Magnitude of force per unit length on the middle wire ‘B’ is given by
A long solenoid of 50 cm length having100 turns carries a current of 2.5 A. The magnetic field at the centre of the solenoid is: μ 0 = 4 π × 10 − 7 TmA − 1
A wire of length L metre carrying a current of l ampere is bent in the form of circle. Its magnetic moment is
A toroidal solenoid with 400 turns and mean radius of 4.0 cm has air core. The current in the winding that is required to set up a magnetic field of 4.0 m T in the air core is
The number of α a n d β particles emitted in the conversion of T 90 232 h t o 82 208 P b are
A wire PQR is bent as shown in figure and is placed in a region of uniform magnetic field B. The length of PQ = QR = l. A current I ampere flows through the wire as shown. The magnitude of the force on PQ and QR will be
Two particles, each of mass m and charge q, are attached to the two ends of a light rigid rod of length 2R. The rod is rotated at constant angular speed about a perpendicular axis passing through its centre. The ratio of the magnitudes of the magnetic moment of the system and its angular momentum about the centre of the rod is
The magnitude of magnetic field at a point having perpendicular distance 50 mm from a long straight conducting wire carrying a current of 3A is
Which of the following quantity remains constant for a charge particle moving inside a magnetic field,
A thin circular disk of radius R is uniformly charged with density σ > 0 per unit area. The disk rotates about its axis with a uniform angular speed ω . The magnetic moment of the disc is :
Two toroids 1 and 2 have total no. of turns 200 and 100 respectively with average radii 40 cm and 20 cm respectively. If they carry same current i, the ratio of the magnetic fields along the two loops is,
A uniform magnetic field of 0.3 T is established along the positive Z-direction. A rectangular loop in XY plane of sides 10 cm and 5 cm carries a current of I = 12 A as shown. The torque on the loop is :
An electron moves straight inside a charged parallel plate capacitor of uniform charge density σ . The space between the plates is filled with uniform magnetic field of intensity B, as shown in the figure. Neglecting effect of gravity, the time of straight line motion of the electron in the capacitor is :
A proton and an α − particle , accelerated through the same potential difference, enter a region of uniform magnetic field normally. If the radius of the proton orbit is 10 cm, then that of α – orbit is
A current carrying loop ABCDA is carrying a current I. O is the centre of the semi circle ADC, ABC = 90 0 and AB = BC = l. Then magnetic induction at o is
A charged particle moves with velocity v = a i ^ + d j ^ in a magnetic field B = A i ^ + D j ^ the force acting on the particle has magnitude F
A proton having kinetic energy ‘K’ is moving in a circular orbit of radius ‘R’ in a uniform magnetic field. Then the radius of an α – particle moving in a circular orbit with same kinetic energy in same magnetic field will be
A current carrying insulated wire is bent in the form of a circular loop and magnetic field at the centre of the loop is found to be 2 μ T . Now the some wire is bent into a loop of three turns. Then new magnetic field at its centre will be
In the figure, the force on the wire ABC in the uniform magnetic field (B = 2 tesla) will be
The magnetic field existing in a region is given by B = B 0 1 + x l k ^ . A square loop of edge l and carrying current I is placed with its edges parallel to the x and y axes. The magnitude of the net magnetic force experienced by the loop is
A charged particle, carrying a charge Q moves with velocity 2 m/s in x-y plane in a uniform magnetic field B = i ^ + 2 j ^ + 3 k ^ T . Then magnitude of component of magnetic force experienced by the particle is zero
A large metal sheet carries on electric current along its surface current per unit length is ‘ λ ‘ . Then magnetic induction near the metal sheet is
An electron beam moves undeflected in a Lorentz Field given by σ .Then the velocity of electron beam is
The ratio of magnetic induction on the axis of a long straight current carrying solenoid at a point on the end to that at the center of the solenoid is
A charged particle of mass 10 – 3 kg and charge 10 – 5 C enters a magnetic field of induction 1 T. If g = 10 m s – 2 , for what value of velocity will it pass straight through the field without deflection?
A current of 1/(4 π ) ampere is flowing in a long straight conductor. The line integral of magnetic induction around a closed path enclosing the current carrying conductor is
A short current carrying solenoid has a magnetic dipole moment M . P is a point on its axial line at a distance d from the north-pole and at a distance 2 d from the south-pole. The magnetic induction at P is
Which of the following cyclotrons gives a proton beam of highest possible energy? The one having
A circular coil of one turn carrying a current produces a magnetic field of induction of magnitude B at the center. If there were another circular coil of one turn whose area is double that of the area of the first coil and carries the same current, the magnitude of the magnetic induction at the center will be
A long wire is bent into the shape PQRST as shown in the following figure with QRS being a semicircle with centre O and radius r metre. A current of I ampere flows through it in the direction P Q R S T . Then the magnetic induction at the point O of the figure in vacuum is
The dipole moment of a current carrying loop does not depend upon
A horizontal rod of mass 10 g and length 10 cm is placed on a smooth plane inclined at an angle of 60 0 with the horizontal with the length of the rod parallel to the edge of the inclined plane. A uniform magnetic field of induction B is applied vertically downwards. If the current through the rod is 1.73 ampere, the value of B for which the rod remains stationary on the inclined plane is
Two identical particles having the same mass m and charges +q and -q separated by a distance d enter in a uniform magnetic field B directed perpendicular to paper inwards with speeds v 1 and v 2 as shown in figure. The particles will not collide if
In the diagram shown below, what is the magnetic field at the point O? (straight wires have infinite length)
is a straight wire having current 2I, and ABDE coplanar with PQ is the combination of wires and circular arc having current I. If BC is R 2 and C is at distance R from PQ, then magnetic field at C is
A charged particle of charge q and mass m enters perpendicularly to a region of transverse magnetic field B. If length of region in which magnetic field is acted is 2 m v q b , then deflection of charge when it comes out from field is
The average radius of an air cored toroid is 0.1 m and it has 500 turns. If it carries 0.5 ampere current, then the magnetic field inside it is :
An electron moving with a speed u along the positive x-axis at y = 0 enters a region of uniform magnetic field which exists to the right of y-axis. The electron exits from the region after some time with the speed v at coordinate y, then
Two parallel wires carrying equal currents in opposite directions are placed at x = ±a parallel to y-axis with z = 0. Magnetic field at origin O is B 1 and at P (2a, 0, 0) is B 2 . Then, the ratio B 1 B 2 is
A uniform current carrying ring of mass m and radius R is connected by a massless string as shown in Fig. A uniform magnetic field B 0 exists in the region to keep the ring in horizontal position, then the current in the ring is (l = length of string)
A proton is projected with kinetic energy 80 Mev in a uniform magnetic field making an angle of 30 0 with the field and pitch of its trajectory is found to be 1m. What will be the pitch of an α-particle if it is projected with same kinetic energy in the same magnetic field making an angle of 60 o with the field?
A small circular ring of radius 1 cm is carrying a current of 10A. P is point on the axis of the ring at a distance of 1m from its centre. Then magnitude induction at P is
A copper ring carrying a current is placed in a uniform magnetic field in such a way that the ring experiences maximum possible torque of 2 N-m. Now the ring is rotated through an angle of 60 o about a diameter which is perpendicular to the field direction. In this position torque experienced by the ring will be
A proton is moving in a circular path with kinetic energy 8 MeV in a uniform magnetic field. What will be the kinetic energy of an α – particle if it moves in a circular path of same radius in the same magnetic field?
A current carrying circular ring, when placed in a uniform magnetic field of 0.25 T with one diameter perpendicular to the field experiences a torque of 0.3 N-m, when the ring is rotated about this diameter through an angle of 90 o , it experiences a torques of 0.4 N-m. Then magnetic dipole moment of the ring is
A charged particle is projected with velocity v in a uniform magnetic field making an angle of 45 0 with the field. The particle followed a helical path of radius 10 cm. If the same particle is projected with velocity 2V in the same magnetic field making an angle of 60 0 with the field, radius of helical path followed by the particle will be
Current sensitivity of a moving coil galvanometer can be increased by decreasing
A charged particle is projected in a uniform magnetic field making an angle of 30 o with the field, and radius of its trajectory is found to be 50 cm. When the same particle is projected in the same magnetic field making an angle of 60 o with the field, what will be the radius of the trajectory?
A square loop ABCD of side length 2m is placed mean a very long straight conductor PQ carrying a current of 10 A as shown in figure. The square loop is carrying a current of 10 A and the conductor PQ lies in the plane of the loop ABCD. Then the magnetic force exerted by the square loop on the straight conductor is
One end of a straight copper rod, carrying a current of 2A, is at the origin and the other end is at the point A whose co ordinates are (1m, 1m, 1m). A uniform magnetic field B = 1.5 i ^ T exists in that region, Direction of current in the rod is from the origin to point A. Then magnitude of force experienced by the rod is
A galvanometer has a resistance of 20 ohms , a current of 2 mA gives full scale deflection. The necessary resistance in ohms to convert this galvanometer into voltmeter of range 0 – 3 V is
The Earth’s magnetic field at a given point is 0.5 G. This field is to be annulled by magnetic induction at the centre of a circular coil of radius 5 cm. The current required to be flown in the loop is nearly
The loop shown in figure in carrying a current I the magnetic induction at the common centre O of the semi circles is B. Now the wire of the loop is bent to form a circular ring which is carrying the same current I. Then magnetic induction at the centre of the ring will be
If a charged particle goes with uniform acceleration in a region containing uniform electric field ( E ) and uniform magnetic field ( B ) then
Magnetic field at the centre of a long current carrying solenoid is 8.28 × 10 − 4 T . If length of the solenoid is halved and number of turns is doubled, what will be the magnetic field near the ends of the solenoid?
A cathode ray beam is bent in a circle of radius 2.0 cm by a uniform field with B = 9.1 × 10 − 3 T . What is the speed of the electrons?
A galvanometer of resistance 30 ohm is converted into an ammeter of range 2.8 A by connecting a shunt resistance 12 ohm to the galvanometer. What can be the range of ammeter if a resistance 6 ohm is connected in parallel to the shunt 12 ohm?
Two long parallel current carrying conductors are carrying currents 2A and 4A in ϕ opposite directions. If the separation between the conductors is 1m, find the magnetic induction at a point midway between the wires.
A proton is projected with a velocity of V = 200 3 i ^ + 4 j ^ m / s in a uniform magnetic field of 5 K ^ T . Then magnitude of force experienced by the proton just after projection is
The L-shaped conductor ABC is carrying a current 5 A and it is placed in a uniform magnetic field of B = 0.5 T. If length AB = 3m and BC = 4m, the magnetic force experienced by the conductor ABC is
An electron and a proton are injected into a uniform magnetic field perpendicular to it with the same momentum. What is the nature of their trjaectories?
Two charged particles 1 and 2 with same velocity, enter a region of uniform magnetic field in a direction perpendicular to the field. If the particles have the same mass, then
The magnetic flux density B at a distance r from a long straight wire carrying current varies with distance r as shown in Fig. :
The magnetic field at the centre of a current-carrying circular coil depends on the radius R of the coil as :
A particle carrying a charge equal to 100 times the charge on an electron, is rotating per sec in a circular path of radius 0.8 m. The value of the magnetic field produced at the centre will be :
A given length of a wire carries a steady current. It is bent first to form a circular plane coil of one turn. If a loop of same length is now bent more sharply to give a double loop of smaller radius, the magnetic field at the centre caused by the same current is :
Two concentric coils of 10 turns each are situated in the same plane. Their radii are 20 cm and 40 cm and they carry respectively 0.2 and 0.3 ampere current in opposite directions. The magnetic field (in Wb/m 2 ) at the centre is :
Magnetic field at point A would be :
A wire is bent in the form of a quadrant of circle of radius ‘a’ as shown in the Fig. 8.93. The magnetic field at centre O due to current i is :
The value of the magnetic field at a distance x from along straight current-carrying conductor is proportional to :
Fig. shows two straight long wires insulated from each other along the axes x and y carrying equal current I. AB and CD are lines in the plane of the axes and at 45° with the axes. The magnetic field of the system is zero on the line :
The wire loop carries a current i as shown in Fig. The magnetic field at the centre O is :
Two identical long conducting wires AOB and COD are placed at right angle to each other, with one above other such that ‘O’ is their common point for the two. The wires carry I 1 and I 2 currents respectively. Point ‘P’ is lying at distance ‘d’ from ‘O’ along a direction perpendicular to the plane containing the wires. The magnetic field at the point ‘ P’ will be :
1 m long wire is folded in form of a circular coil and 100 mA electric current is flowing in it, then magnetic field at a point 1m away from its centre on its axis :
The wire RS is fixed, but PQ is free to move. The wire PQ will have
In a gravity free region of space a charged particle is projected. If the path followed by the particle is a circle, then
A charged particle of mass m, carrying a charge Q is projected from the origin with a velocity V = V o i ^ + j ^ . A uniform magnetic field B = B i ^ exists in that region. Then maximum distance of the particle from x-axis is
The net resistance of a voltmeter should be large to ensure that
A voltmeter has resistance of 2000 Ω and it can measure upto 2 V. If we want to increase its range to 10 V then the required resistance in series will be
A galvanometer has 30 divisions and sensitivity 16 μ A / d i v . It can be converted into a voltmeter to read 3 V by connecting
A galvanometer has 30 divisions and sensitivity 16 μA / div . It can be converted into a voltmeter to read 3 V by connecting
A galvanometer whose resistance is 120 Ω gives fuIl scale deflection with a curren of 0.05 A so that it can read a maximum current of 10 A. A shunt resistance is added in parallel with it. The resistance of the ammeter so formed is
A galvanometer coil has a resistance 90 Ω and full scale deflection current 10 mA. A 910 Ω resistance is connected in series with the galvanometer to make a voltmeter. If the least count of the voltmeter is 0.1 V the number of divisions on its scale is
An α-particle and a proton are projected in a uniform magnetic field in a direction perpendicular to the field. If r be the radius of circular path energy of α-particle to that of proton is
A charged particle of mass 2 x 10 -12 kg carrying a charge of 4 x 10 -9 coul is projected in a uniform magnetic field of 2 x 10 -4 tesla with a velocity of 10 m/s making an angle of 60° with the magnetic field. If acceleration due to gravity in that field is zero, then length of path praversed by the particle in 1 minute is
A particle is projected in a gravity force space where a uniform magnetic field exists. if the trajectory of the particle is a straight line, then the particle
In a gravity free space a charged particle is projected. If the kinetic energy of the particle charges but it suffers no deviation, then in that region of space
A particle is projected in a gravity free space. If the particle suffers deviation but its kinetic energy remains unchanged, then in that region
A current carrying straight conductor is placed in a uniform magnetic field and the force experienced by it is 10 3 N. If the maximum possible force experienced by the conductor, when placed in the same magnetic field is 20 N, then in the first case the angle between the direction of current in the conductor and the magnetic field is
A charged particle is moving in a region where a uniform gravitational field and uniform magnetic field exist (Electric field is zero). Then path of the particle may be
A charged particle carrying a charge 2µC is fired in a gravity free space where mutually perpendicular electric and magnetic field exist. If E = 3 i ^ – 3 j ^ v / m and B = a i ^ + 5 j ^ Tesla and the particle passes undeviated, then magnitude of magnetic field is
A rectangular coil ABCD carrying a current of 2A is placed in a uniform magnetic field of induction magnetic field of induction B = 2 T in a gravity free space. Length Ab = CD = 4 m and length BC = Ad = 3 m. Then tensions induced in the sides AB and BC are respectively.
A current carrying straight conductor is placed in a uniform magnetic field and force experienced by the conductor is 6N. When the conductor is rotated through an angle of 90° in the plane containing the rod and the field, force experienced by the rad is 8 N. Then maximum possible forced experienced by the conductor when placed in the same magnetic field is
A current carrying conductor AB is bent in a form of a semi circle of radius r and it is placed in a uniform magnetic field of induction B as shown in figure. Then force experienced by the conductor is
A triangular loop in the form of an equilateral triangle is carrying a current of 2A.The loop is placed in a uniform magnetic field of induction 1.5 T, with its plane perpendicular to the magnetic field as shown in figure. Then net force experienced by the loop is
Magnetic induction at a distance of 20 cm from the axis of long straight wire carrying a current i is 5 µT. Then what is the magnetic induction at a distance 40 cm from the axis of a long straight wire carrying a current 2i?
Magnetic induction on the surface of a long current carrying wire of radius R is 8 µT. Then magnetic induction at a distance R/4 from the axis of the conductor is
A wire length π 2 m , carrying a current of 2A is bent in the form of a circular are which subtends on angle of 45° at its centre. Then magnetic induction at the centre is
When a 12 Ω resistor is connected with a moving coil galvanometer, then its deflection reduces from 50 divisions to 10 divisions. The resistance of the galvanometer is
A, B and C are three infinite current carrying wires carrying 2A, 3A and I as shown in figure. P is a point midway between wires B and C. For what value of P magnetic induction at P will be zero.
A proton moving with a constant velocity passes through a region of space without any change in its velocity. If E and B represent the electric and magnetic field intensities respectively, then this region of space may not have
A galvanometer can be used as a voltmeter by connecting a
A square frame, made of copper wire is carrying a current i = 12 A . Length of side of the square is 1 m. If the frame is placed in a magnetic region where B 1 = 1 μT and B 2 = 2 μT , then net force experienced by the square frame is
The resistance of an ammeter is 13 Ω and its scale is graduated for a current up to 100 A. After an additional shunt has been connected to this ammeter it becomes possible to measure currents up to 7 50 A by this meter. The value of shunt resistance is
A particle of charge q and mass m is moving along the x-axis with a velocity v and enters a region of electric field E and magnetic field B as shown in figures below. For which figure the net force on the charge may be zero?
A uniform magnetic field B and a uniform electric field E act in a common region. An electron is entering this region of space . The correct arrangement for it to escape undeviated is
If a proton is projected in a direction perpendicular to a uniform magnetic field with velocity v and an electron is projected opposite to the direction of the lines of force, what will happen to proton and electron?
A homogeneous electric field E and a uniform magnetic field B are pointing in the same direction. A proton is projected with its velocity parallel to E . It will
An electron is travelling horizontally towards east. A magnetic field in vertically downward direction exerts a force on the electron along
An electron is moving along positive x-axis. To get it moving on an anticlockwise circular path in x-y plane, a magnetic field is applied
A proton (mass m and charge +e) and an α -particle (mass 4m and charge +2e) are projected with the same kinetic energy at right angles to the uniform magnetic field. Which one of the following statements will be true?
A deuteron of kinetic energy 50 keV is describing a circular orbit of radius 0.5 metre in a plane perpendicular to magnetic field B . The kinetic energy of the proton that describes a circular orbit of radius 0.5 metre in the same plane with the same B , is
An election moving with a speed u along the positive x-axis at y = 0 enters a region of uniform magnetic field which exists to the right of y-axis. The electron exits from the region after some time with the speed v at coordinate y, then
If a particle of charge 10 − 12 C moving along the x-direction with a velocity 10 5 m/s experiences a force of 10 − 10 newton in y-direction due to a magnetic field, then the minimum magnitude of magnetic field is
A proton and a deuteron, both having the same kinetic energy, enter perpendicularly into a uniform magnetic field B. For motion of proton and deuteron on circular path of radius R p and R d , respectively, the correct option is
A very long wire carrying a current of 5A, lies a long the Z axis. Then magnetic induction at the point P (3, 4, 1) m is
If a particle of mass 0.6 g and having charge of 25 nC is moving horizontally with a uniform velocity 1 .2 × 10 4 ms − 1 in a uniform magnetic field, then the value of the magnetic induction is g = 10 m s − 2
An electron, a proton, a deuteron and an alpha particle, each having speed v, are in a region of constant magnetic . field perpendicular to the direction of the velocities of the particles. The radius of the circular orbits of these particles are respectively R e , R p , R d and R α . It follows that
An electron gun ejects electrons at an angle of 45° with magnetic field boundary as shown. Find the angular deviation of electrons as it comes out of field.
Three infinitely long straight current carrying wires, each carrying a current I, are placed at the vertices of an equilateral triangle of side 1 m. Then resultant magnetic induction at the centroid of the triangle is
A charged particle enters a uniform magnetic field with velocity v 0 perpendicular to it. The length of magnetic field is x = 3 2 R , where R is the radius of the circular path of the particle in the field. The magnitude of change in velocity of the particle when it comes out of the field is
A proton accelerated by a potential difference 500 kV moves though a transverse magnetic field of 0.51 T as shown in figure. The angle θ through which the proton deviates from the initial direction of its motion, is
A particle of mass m and charge q moves with a constant velocity v along the positive x-direction. It enters a region containing a uniform magnetic field B directed along the negative z-direction, extending from x = a to x = b. The minimum value of v required so that the particle can just enter the region x > b, is
A current carrying square loop ABCD is placed at a distance a from on infinitely long current carrying long straight conductor PQ as shown in the figure. The conductor PQ lies in the plane of the loop. Then
A current carry square loop ABCD is placed at a distance a from an infinitely long current carrying long straight conductor PQ as shown in the figure. The conductor PQ lies in the plane of the loop. Then
A particle having mass m, charge q, enters a cylindrical region having uniform magnetic field B in the inward direction as shown. If the particle is deviated by 60 0 as it emerges out of the field, then what is the time spent by it in the field?
A particle of mass m having negative charge − q is projected at an angle θ with x-axis. There exists a uniform electric field E and a uniform magnetic field B along x-axis. The particle will return to its initial point after n complete revolutions in time t. What is n here?
A uniform magnetic field B = 3 i ^ + 4 j ^ + k ^ exists in region of space. A semicircular wire of radius 1 m carrying current 1 A having its centre at (2, 2, 0) is placed in x-y plane as shown in figure. The force on semicircular wire will be
A parabolic section of wire OA is located in the x-y plane and carries current I = 12 A. A uniform magnetic field B = 4.0 T making an angle 60 0 with x axis exists in x-y plane. Calculate the magnetic force on the wire OA. Coordinates of A are (0.25 m, 1 m).
A conducting rod of mass 50 g and length 10 cm can slide without friction on two long, horizontal rails. A uniform magnetic field of magnitude 5 mT exists in the region as shown. A source S is used to maintain a constant current 2 A through the rod. If motion of the rod starts from the rest, its speed after 10 s from the start of the motion will be
A ring of radius R, made of an insulating material, carries a charge Q uniformly distributed on it. If the ring rotates about the axis passing through its centre and normal to plane of the ring with constant angular speed ω , then the magnitude of the magnetic moment of the ring is
A straight wire carrying a current i 1 amperes runs along the axis of a circular coil carrying current i 2 amperes. Then the force of interaction between the two current carrying conductors is
An infinitely long, straight conductor AB is fixed and a current is passed through it. Another movable straight wire CD of finite length and carrying current is held perpendicular to it and released. Neglect weight of the wire
A rectangular loop carrying a current i is situated near a long straight wire such that the wire is parallel to the one of the sides of the loop and is in the plane of the loop. If a steady current I is established in wire as shown in figure, the loop will
Two parallel wires are carrying electric currents of equal magnitude and in the same direction. They exert
Two long and parallel wires are at a distance of 0.1 m and a current of 5 A is flowing in each of these wires. The force per unit length due to these wires will be
Two straight parallel wires, both carrying 10 A current in the same direction, attract each other with a force of current 1 × 10 − 3 N . If both currents are doubled, the force of attraction will be
The unit of electric current “ampere” is the current which when flowing through each of two parallel wires spaced 1 m apart in vacuum and of infinite length will give rise to a force between them equal to
Three long, straight and parallel wires carrying current are arranged as shown in figure. The force experienced by 10 cm length of wire Q is
Two parallel wires in free space are 10 cm apart and each carries a current of 10 A in the same direction. The force one wire exerts on the other per metre of length is
Two long parallel wires carrying equal current separated by 1 m, exert a force of 2 × 10 − 7 N / m on one another. The current flowing through them is
What is the net force on the square coil?
Two long parallel copper wires carry current of 5 A each in opposite directions. If the wires are separated by a distance of 0.5 m, then the force per unit length between the two wires is
A long wire A carries a current of 10 A. Another long wire B, which is parallel to A and separated by 0.1 m from A, carries a current of 5 A, in the opposite direction to that in A. What is the magnitude and nature of the force experienced per unit length of B? μ 0 = 4 π × 10 − 7 Wb / A − m
A, B and C are parallel conductors of equal length carrying currents I, I and 2I, respectively. Distance between A and B is x. Distance between B and C is also x. F 1 is the force exerted by B on A and F 2 is the force exerted by C on A. Choose the correct option.
There long straight wires A, B and C are carrying current as shown figure. Then the resultant force on B is directed
Two parallel wires of length 9 m each are separated by a distance 0.15 m. If they carry equal current in the same direction and exerts a total force of 30 × 10 − 7 N on each other, then the value of current must be
Three long, straight parallel wires carrying current, are arranged as shown in figure. The force experienced by a 25 cm length of wire C is
Two long conductors 10 cm apart carry currents in the ratio 1 :2 in the same direction. The magnetic field midway between them is 2 × 10 − 3 T The force on unit length of any one conductor will be
A long straight wire carrying current I 1 is placed in the plane of a ribbon carrying current I 2 parallel to the wire. The width of ribbon is b. The straight conductor is placed at a distance a from the nearer edge of ribbon. Find the force of attraction per unit length between the two.
A long horizontal wire P carries a current of 50 A. It is rigidly fixed. Another fine wire Q is placed directly above and parallel to P. The weight of wire Q is 0.075 N/m and carries a current of 25 A. Find the position of wire Q from P so that the wire Q remains suspended due to magnetic repulsion.
A current flows in a .conductor from east to west. The direction of the magnetic field at a points above the conductor is
The current is flowing in south direction along a power line. The direction of magnetic field above the power line (neglecting earth’s field) is
A straight section PQ of a circuit lies along the X-axis from x = − a 2 to x = a 2 and carries a steady current i. The magnetic field due to the section PQ at a point X = + a will be
A long straight vertical wire carries a current of 10 A flowing upwards through it at a place where the horizontal component of the earth’s magnetic induction is 0.3 gauss. Then the total magnetic induction at a point 5 cm from the wire due magnetic north of the wire is
A long vertical wire in which a current is flowing produces a neutral point with the earth’s magnetic field at a distance of 5 cm from the wire. If the horizontal component of the earth’s magnetic induction is 0.18 gauss, then the current in the wire is
If a current of 5 A is passed through a straight wire of length 6 cm, then the magnetic induction at a point 5 cm from the either end of the wire is
In figure, two long parallel wires carry equal currents in opposite directions. Point O is situated midway between the wires . X-Y plane contains the two wires and the Z-axis comes normally out of the plane of paper. P is a point such that the magnetic field B at P is zero . Then P lies
Two straight long conductors AOB and COD are perpendicular to each other and carry currents I 1 and I 2 . The magnitude of the magnetic induction at a point P at a distance d from the point O in a direction perpendicular to the plane ABCD is
Two very thin insulated metallic wires placed along X and Y-axis carry equal currents as shown in figure. AB and CD are lines at 45 0 with the axes with origin of axes at O. The magnetic fields will be zero on the line
Current I 1 and I 2 flow in the wires shown in figure. The field is zero at distance x to the right of O. Then
Two long straight wires are set parallel to each other. Each carries a current i in the same direction and the separation between them is 2r. The intensity of the magnetic field midway between them is
Two infinitely long, thin, insulated, straight wires lie in the x-y plane along the x and y-axes. Each wire carries a current I, respectively; in the positive x-direction and positive y-direction. The magnetic field will be zero at all points on the straight line
An infinitely long straight wire is carrying current I and another wire which is parallel to the first wire , is carrying current 2I in the same direction.The wires produce a magnetic field B at the midpoint. What will be the field when 2I wire is switched off?
Two long parallel wires P and Q are both perpendicular to the plane of the paper with distance 5 m between them. If P and Q carry current of 2.5 A and 5 A, respectively, in the same direction, then the magnetic field at a point half way between the wires is
Two parallel wires carrying equal currents in opposite directions are placed at x = ±a parallel to y-axis with z = 0. Magnetic field at origin O is B 1 and at P (2a, 0, 0) is B 2 . Then the ratio B 1 /B 2 is
ABCD is a square loop made of a uniform conducting wire. The current enters the loop at A and leaves at D. The magnetic field is
Two parallel, long wires carry currents i 1 and i 2 with i 1 > i 2 . When the current are in the same direction, the magnetic field at a point midway between the wire is 10 mT. If the direction of i 2 is reversed, the field becomes 30 mT. The ratio i 1 /i 2 is
A straight wire current element is carrying current 100 A, as shown in figure. The magnitude of magnetic field at point P which is at perpendicular distance 3 − 1 m from the current element if end A and end B of the element subtend angle 30 0 and 60 0 at point P, as shown, is
The magnetic field at the centre of an equilateral triangular loop of side 2L and carrying a current i is
Two wires AO and OC carry equal currents i as shown in figure. One end of both the wire extends to infinity. Angle AOC is α . The magnitude of magnetic field at a point P on the bisector of these two wires at a distance r from point O is
An infinitely long wire carrying current I is along Y axis such that its one end is at point A (0, b) while the wire extends upto + ∞ . The magnitude of magnetic field strength at point (a, 0) is
An electron is projected with a velocity v 0 in a uniform electric field E perpendicular to the field. Again it is projected with velocity v 0 perpendicular to a uniform magnetic field. If r 1 and r 2 are initial radii of curvature just after entering in the electric field and magnetic field respectively, then the ratio r 1 /r 2 is
The magnetic field at O due to current in the infinite wire forming a loop as shown in figure is
A current f flows in a thin wire shaped as regular polygon of n sides which can be inscribed in a circle of radius R. The magnetic field induction at the centre of polygon due to one side of the polygon is
Two long wires PQR and MNP carry equal current I as shown such that QR and NP are parallel. Find the magnetic field at origin O.
The field normal to the plane of a wire of n turns and radius r which carries a current i is measured on the axis of the coil at a small distance h from the centre of the coil. This is smaller than the field at the centre by the fraction
An infinitely long conductor PQR is bent to form a right angle as shown. A current f flows through PQR. The magnetic field due to this current at the point M is H 1 . Now another infinitely long straight conductor QS is connected at Q so that the current is I/2 in QR as well as in QS. The current in PQ remains unchanged. The magnetic field at M is now H 2 . The ratio H 1 /H 2 is given by
A long straight wire along the z-axis carries a current I in the negative z direction. The magnetic vector field B at a point having coordinates (x, y) in the z = 0 plane is
The magnetic field at the centre of coil of n turns, bent in the form of a square of side 2 l , carrying current i, is
In the current carrying conductor shown in figure, the magnetic induction at the centre O, of the semicircular part is
At a distance of 10 cm from a long straight wire carrying current, the magnetic field is 0.04 T. At the distance of 40 cm, the magnetic field will be
A long straight non-conducting string carries a charge density of 40 μC/m. It is pulled along its length at a speed of 300 m/s. What is the magnetic field at a normal distance of 5 mm from the moving string?
A square conducting loop of side length L carries a current I. The magnetic field at the centre of the loop is
A non-planar loop of conducting wire carrying a current i is placed as shown in the figure. Each of the straight sections of the loop is of length 2a. The magnetic field due to this loop at the point P (a, 0, a) points in the direction
Two infinitely current carrying insulated wires AB and CD are carrying same current I. The wires cross each other at right angles as shown in figure. Three identical conductors P 1 Q 1 , P 2 Q 2 and P 3 Q 3 , carrying same current are placed a shown in figure and the forces acting on them are F 1 , F 2 and F 3 respectively. Then select the correct option.
A solid cylindrical conductor A of radius R is carrying a current 2i. Cylindrical metallic shell of radius 2R which carries a current i as shown in the figure. If P is a point at a distance r from the common axis and B P is the magnetic induction at P, then
An electron is revolving round a proton, producing a magnetic field of 16 Wb/m 2 in a circular orbit of radius 1 A o . Its angular velocity will be
A small ring of radius ‘a’ is carrying i, P is a point on its axis at a large distance x from its center. Mathematic induction at P is found to be B 1 . If the radius is doubled and current is also doubled. Also the distance of P from the center of the ring is doubled. Then find new magnetic induction at P.
A particle carrying a charge equal to 100 times the charge on an electron is making one revolution per second in a circular path of radius 0.8 m. The value of the magnetic field produced at the centre will be ( μ 0 = permeability for vacuum)
In a hydrogen atom, an electron moves in a circular orbit of radius 5 .2 × 10 − 11 m and produces a magnetic induction of 12.56 T at its nucleus. The current produced by the motion of the electron will be Given μ 0 = 4 π × 10 − 7 Wb / A − m
A neutral point is obtained at the centre of a vertical circular coil carrying current. The angle between the plane of the coil and the magnetic meridian is
In hydrogen atom, an electron is revolving in the orbit of radius 0 .53 A o with 6.6 × 10 15 rotations/second. Magnetic field produced at the centre of the orbit is
An electron moves in a circular orbit with a uniform speed v. It produces a magnetic field B at the centre of the circle. The radius of the circle is proportional to
A circular loop is kept in that vertical plane which contains the north-south direction. It carries a current that is towards north at the topmost point. Let A be a point on the axis of the circle to the east of it and B a point on this axis to the west of it. The magnetic field due to the loop
A current carriyng straight conductor OA lies along x-axis. In that region a magnetic field of induction B exists whose direction is inward and magnitude of ‘B’ increases as we are moving along positive x-axis. If C be the mid point of the rod OA, then select the correct option.
Due to the flow of current in a circular loop of radius R, the magnetic induction produced at the centre of the loop is B. The magnetic moment of the loop is ( μ 0 = permeability constant)
The magnetic induction at point O due to the current carrying loop is
The magnetic moment of a current carrying loop is 2 .1 × 10 − 25 Am 2 . The magnetic field at a point on its axis at a distance of 1 A o is
Magnetic field due to 0.1 A current flowing through a circular coil of radius 0.1 m and 1000 turns at the centre of the coil is
Due to 10 A of current flowing in a circular coil of 10 cm radius, the magnetic field produced at its centre is 3 .14 × 10 − 3 Wb / m 2 . The number of turns in the coil will be
Magnetic field intensity at the centre of coil of 50 turns, radius 0.5 m and carrying a current of 2 A is
One metre length of wire carries a constant current. The wire is bent to form a circular loop. The magnetic field at the centre of this loop is B. The same is now bent to form a circular loop of smaller radius to have four turns in the loop. The magnetic field at the centre of this new loop is
An arc of a circle of radius R subtends an angle π 2 at the centre. It carries a current i. The magnetic field at the centre will be
The earth’s magnetic field at a given point is 0 .5 × 10 − 5 Wb / m 2 . This field is to be annulled by magnetic induction at the centre of a circular conducting loop of radius 5 .0 cm. The current required to be flown in the loop is nearly
A long wire carries a steady current. It is bent into a circle of one turn and the magnetic field at the centre of the coil is B. It is then bent into a circular loop of n turns. The magnetic field at the centre of the coil will be
The ratio of the magnetic field at the centre of a current carrying coil of the radius a to that at a distance a from centre of the coil and on the axis of the coil is
The magnetic field due to a current canying circular loop of radius 3 cm at a point on the axis at a distance of 4 cm from the centre is 54 μT. What will be its value at the centre of the loop?
Two concentric coplanar circular loops of radii r 1 and r 2 carry currents i 1 and i 2 , respectively, in opposite directions (one clockwise and the other anticlockwise.) The magnetic induction at the centre of the loops is half of that due to i 1 alone at the centre. If r 2 = 2r 1 , the value of i 2 /i 1 is
Two concentric coplanar circular loops of radii r 1 and r 2 cany currents i 1 and i 2 , respectively, in opposite directions (one clockwise and the other anticlockwise.) The magnetic induction at the centre of the loops is half that due to i 1 alone at the centre. If r 2 = 2r 1 , the value of i 2 /i 1 is
Two concentric coplanar circular loops of radii r 1 and r 2 cany currents i 1 and i 2 , respectively, in opposite directions (one clockwise and the other anticlockwise.) The magnetic induction at the centre of the loops is half that due to i 1 alone at the centre. If r 2 = 2r 1 , the value of i 2 /i 1 is
Two concentric circular coils of ten turns each are situated in the same plane. Their radii are 20 cm and 40 cm and they carry 0.2 A and 0.3 A current, respectively, in opposite direction. The magnetic field in weber/m 2 at the centre is
The loop ABC, has the shape of an isoceles right angled triangle. If is carrying a current i. If AB = BC = l, then induction at D is
ABCD is a square loop having length of side ‘l’ and it is carrying a current i. The loop is placed in a region where a magnetic field B = − B o 1 + x 2 l 2 k ^ exists as shown in figure. Then net force experienced by the loop is
A wire is bent in the form of a circular arc with a straight portion AB. Magnetic induction at O when current I is flowing in the wire, is
A current i ampere flows in a circular arc of wire whose radius is R, which subtend an angle 3 π / 2 radian at its centre. The magnetic induction B at the centre is
A square loop having length of side 1 m is liying in the xy plane. A uniform magnetic field B = 2 i ^ − 3 j ^ + k ^ T exists in that region of space. If the loop carries a current of 2A, the magnitude of torque experienced by the loop is,
The magnetic induction at the centre O in the figure shown is
In the figure shown, the magnetic induction at the centre of the arc due to the current in portion AB will be
The magnetic induction at the centre O shown in the figure is
A wire carrying current i is shaped as shown. Section AB is a quarter circle of radius r and current is flowing from A to B. The magnetic field is directed
A and B are two concentric circular conductors of centre O and carrying currents i 1 and i 2 as shown in the figure. If ratio of their radii is 1 : 2 and ratio of the flux densities at O due to A and B is 1 : 3, then the value of i 1 /i 2 is
A part of a long wire carrying a current i is bent into a circle of radius r as shown in figure. The net magnetic field at the centre O of the circular loop is
The resistances of three parts of a circular loop are as shown in the figure. The magnetic field at the centre O is
In the figure, what is the magnetic field at the point O?
Considering magnetic field along the axis of a circular loop of radius R, at what distance from the centre of the loop is the field one eighth of its value at the centre?
In figure, infinite conducting rings each having current i in the direction shown are placed concentrically in the same plane as shown in the figure. The radius of rings are r , 2 r , 2 2 r , 2 3 r . …. ∞ The magnetic field at the centre of rings will be
Two circular coils X and Y have equal number of turns and carry equal currents in the same sense and subtend same solid angle at point O. The smaller coil X is midway between O and Y. If we represent the magnetic induction due to bigger coil Y at O as B Y and that due to smaller coil X at O as B X , then
Two identical wires A and B have the same length l and carry the same current I. Wire A is bent into a circle of radius R and wire B is bent to form a square of side a. If B 1 and B 2 are the values of magnetic induction at the centre of the circle and the centre of the square respectively, then the ratio B 1 /B 2 is
Find the magnetic field at the centre of the circular loop as shown in the figure, when a single wire is bent to form a circular loop and also extends to form straight sections.
In a bent wire shown in figure, a current I is passed. Find the value of B at the common centre.
A current I flows along the length of an infinitely long, straight and thin-walled pipe. Then
Rank the value of ∮ B . dl for the closed paths shown in figure from the smallest to largest.
An infinite, straight wire has two concentric loops of radii a and b carrying equal currents in opposite directions as shown. The magnetic field at the common centre is zero for
The current in the wire is I. The current comes from infinite parallel to z-axis and finally goes to infinite parallel to y-axis as shown in the figure. Find magnetic field at O in vector form for the following current configurations.
For c = 2a, and a < b < c, the magnetic field at point P will be zero when
A current of 1 / 4 π ampere is flowing in a long straight conductor. The line integral of magnetic induction around a closed path enclosing the current carrying conductor is
In the diagram shown, a wire carries current I. The loop has N turns and part of helical loop on which arrows are drawn is outside the plane of paper. What is the value of the ∮ B . d l ( as in Ampere’s law) on the helical loop shown in the figure?
Cross-section of an infinite cylinder is shown. A current I uniformly distributed over its cross-section is flowing along its length. Now a cylindrical cavity of radius R/2,whose axis is parallel to the axis of the cylinder, is formed inside it. Then
A current i ampere flows along the inner conductor of a coaxial cable and returns along the outer conductor of the cable, then the magnetic induction at any point outside the conductor at a distance r metre from the axis is
A long copper tube of inner radius R carries a current i. The magnetic field B inside the tube is
A long, straight, hollow conductor (tube) carrying a current has two sections A and C of unequal cross-section joined by a conical section B. 1, 2 and 3 are points on a line parallel to the axis of the conductor. The magnetic fields at 1, 2 and 3 have magnitudes B 1 , B 2 and B 3 . Then
A long, straight, hollow conductor (tube) carrying a current has two sections A and C of unequal cross-section joined by a conical section B. 1, 2 and 3 are points on a line parallel to the axis of the conductor. The magnetic fields at 1, 2 and 3 have magnitudes B 1 , B 2 and B 3 . Then
lf a long hollow copper pipe carries a direct current, the magnetic field associated with the current will be
A coaxial cable consists of a thin inner conductor fixed along the axis of a hollow outer conductor. The two conductors carry equal currents in opposite directions. Let B 1 and B 2 be the magnetic fields in the region between the conductors, and outside the conductor, respectively. Then
A long straight metal rod has a very long hole of radius drilled parallel to the rod axis as shown in the figure. If the rod carries a current I, find the magnetic field on axis of hole. Given C is the centre of the hole and OC = c.
An electric current passes through a long straight wire. At a distance 5 cm from the wire the magnetic field is B. The field at 20 cm from the wire would be
A wire in the form of a circular loop of one turn carrying a current produces a magnetic field B at the centre. If the same wire is looped into a coil of two turns and carries the same current, the new value of magnetic induction at the centre is
Lorentz force can be calculated by using the formula
A long solenoid carrying a current produces a magnetic field B along its axis. If the current is doubled and the number of turns per cm is halved, the new value of the magnetic field is
An electron enters a magnetic field whose direction is perpendicular to the velocity of the electron. Then
Two parallel wires carrying currents in opposite direction
Two circular coils 1 and 2 are made from the same wire but the radius of the 1st coil is twice that of the 2nd coil. What is the ratio of potential difference applied across them so that the magnetic field at their centres is the same ?
A beam of electrons passes undeflected through mutually perpendicular electric and magnetic fields. If the electric field is switched off, and the same magnetic field is maintained, the electrons move
A charged particle (charge q) is moving in a circle of radius R with uniform speed v. The associated magnetic moment μ is given by
Under the influence of a uniform magnetic field a charged particle is moving in a circle of radius R with constant speed v. The time period of the motion
A particle of mass m, charge Q and kinetic energy T enters a tranverse uniform magnetic field of induction B . After 3 s, the kinetic energy or the particle will be
A circular coil of radius R carries an electric current. The magnetic field due to the coil at a point on the axis of the coil located at a distance r from the centre of the coil, such that r >> R, varies as
The magnetic force acting on a charged particle of charge − 2 μC in a magnetic field of 2 T acting in y direction, when the particle velocity is 2 i ^ + 3 j ^ × 10 6 ms − 1 , is
The cyclotron frequency of an electron moving in a magnetic field of 1 T is approximately
An α particle and a proton travel with same velocity in a magnetic field perpendicular to the direction of their velocities. Find the ratio of the radii of their circular path.
Axis of a solid cylinder of infinite length and radius R lies along y-axis. It carries a uniformly distributed current I along +y direction. Magnetic field at a point (R/2, y, R/2) is
Consider following coils each of one turn carrying current I. The magnitude of the magnetic induction at X, Y, Z are B 1 , B 2 and B 3 , respectively. Then (assume side of square to be same in each case)
Two insulated wires, carrying currents i 1 a n d i 2 wrapped over a conical frame form the coils 1 and 2. The distance of the apex from the plane of each ring is much much greater than the radius of the ring. If they produce no net magnetic field at the apex P, the value of i 1 i 2 is
Two wires are wrapped over a wooden cylinder to form two co-axial loops carrying currents i 1 and i 2 . If i 2 = 8i 1 , the value of x for B = 0 at the origin O is
Determine the magnetic field at the centre of the current carrying wire arrangement shown in the figure. The arrangement extends to infinity. (The wires joining the successive squares are along the line passing through the centre)
Equal currents i = 1 A are flowing through the wires parallel toy-axis located at x = +1 m, x = +2 m, x = +4 m etc. but in opposite directions as shown. The magnetic field at origin (in T) would be
In figure, AB is a non-conducting rod. Equal charges of magnitude q are fixed at various points on the rod as shown. The rod is rotated uniformly about an axis passing through O and perpendicular to its length such that linear speed of the end A or B of the rod is 3 mis. Magnetic field at O is
A current carrying wire is placed in the, grooves of an insulating semicircular disc of radius R, as shown. The current enters at point A and leaves from point B. Determine the magnetic field at point D.
Three infinitely long wires, each carrying a current 1 A, are placed such that one end of each wire is at the origin, and, one of these wires is along x-axis, the other along y-axis and the third along z-axis. Magnetic induction at point − 2 m , 0 , 0 due to the system of these wires can be expressed as:
In a cylindrical region uniform magnetic field is present as shown in the figure. The cylinder is kept on a horizontal plane and its axis is horizontal. If a charge particle of mass m and charge q is projected horizontally with velocity v through a hole normal to the axis of the cylinder as shown in the diagram. An observer states the particle moves first undeviated and subsequently
There exists a uniform magnetic and electric field of magnitude 1 T and 1 V /m, respectively, along positive y-axis. A charged particle of mass 1 kg and of charge 1 C is having velocity 1 m/s along x-axis and is at origin at t = 0. Then the co-ordinates of particle at time − π seconds will be
A uniform magnetic field of magnitude 1 T exists in region y ≥ 0 along k ^ direction as shown. A particle of charge 1 C is projected from point − 3 , − 1 towards origin with speed 1 m/s. If mass of particle is 1 kg, then co-ordinates of centre of circle in which particle moves are
A charged particle is moving in a circular path in a magnetic field. A resistive force starts acting on the particle whose direction is opposite to the direction of its motion and magnitude is directly proportional to its velocity. Now the particle starts moving in a spiral path, then
A coil having N turns is wound tightly in the form of a spiral with inner and outer radii a and b, respectively. When a current I passes through the coil, the magnetic field at the centre is
A particle of specific charge q m = π C / kg is projected from the origin towards positive x-axis with a velocity of 10 m/s in a uniform magnetic field B = − 2 k ^ T . The velocity v of particle after time t = 1 12 s will be (in m/s)
A neutral particle is initially at rest in a uniform magnetic field B as shown in the diagram. The particle then spontaneously decays into two fragments, one with a positive charge +q and mass 3m and the other with a negative charge -q and mass m. Neglecting the interaction between the two charged particles and assuming that the speeds are much less than speed of light, determine the time (in μs) after the decay at which the two fragments first meet. (use the following data q = 1 μC , B = 2 πμT , m = 10 − 15 kg ) . Both the charges have initial velocities in x-y plane.
A closely wound flat circular coil of 25 turns of wire has diameter of 10 cm which carries current of 4 A. The flux density at the centre of a coil will be
Statement 1: When a charging particle is fired in a magnetic field, the radius of its circular path is directly proportional to the kinetic energy of the particle. Statement 2: The centripetal force on the test charge q 0 is q 0 v 2 B, where v is the velocity of a practical and B is the magnetic field in which the test charge in fired.
An electron is travelling along the x-direction. It encounters a magnetic field in the y-direction. Its subsequent motion will be
Statement 1: The energy of charged particle moving in a uniform magnetic field does not change. Statement 2: Work done by magnetic field on the charge is zero.
Statement 1: If an electron, while coming vertically from outer space, enter the earth’s magnetic field, it is deflected towards west. Statement 2: Electron has negative charge.
Statement 1: The magnetic field at the ends of a very long current carrying solenoid is half of that at the centre. Statement 2: If the solenoid is sufficiently long, the field within it is uniform.
Statement 1: A current I flows along the length of an infinitely long straight and thin walled pipe. Then the magnetic field at any point inside the pipe is zero. Statement 2: ∮ B . d l = μ 0 I
Statement 1: Magnetic field due to an infinite straight conductor varies inversely as the distance from it. Statement 2: The magnetic field at the centre of the circular coil is zero.
A particle of mass M and charge Q is projected in a uniform magnetic field of induction B in a direction perpendicular to the field. Then length of path traversed by the particle in time t= 2 π M Q B i s
Two uncharged parallel plates A and B are at the same electrical potential, and separated by a distance d. A uniform magnetic induction field B acts perpendicular to plane of paper (and parallel to plates) between the plates. Particles, each with charge q, mass m and kinetic energy K are shot through a hole in A directly towards B, particle entering the hole perpendicular to plate A. An ammeter A m connected to B and measures the current collected by the plate B, as the particles hit it. The limiting value of the field B for which the ammeter will stop showing a current is
Two long conductors, separated by a distance d, carry current I 1 and I 2 in the same direction. They exert a force F on each other. Now, the current in one of them is increased to two times and its directions is reversed. The distance is also increased to 3d. The new value of the force between them is
A charged particle of mass m and charge q enters along AB at point A in a uniform magnetic field existing in the rectangular region of size a × b . The particle leaves the region exactly at corner point C. What is the speed v of the particle ?
A charged particle of mass m and charge q enters along AB at point A in a uniform magnetic field existing in the rectangular region of size a × b . The particle leaves the region exactly at corner point C. What is the speed v of the particle ?
Two concentric coils each of radius equal to 2 π cm are placed at right angles to each other. 3 A and 4 A are the current, flowing in each coil, respectively. The magnetic induction, in Wb/m 2 , at the centre of the coils will be μ 0 = 4 π × 10 − 7 Wb / A . m
Two thin long parallel wires separated by a distance b carrying a current i ampere each. The magnitude of the force per unit length exerted by one wire on the other is
A proton and an α -particle enter a uniform magnetic field perpendicularly with the same speed. If proton takes 25 μs to make 5 revolutions, then the periodic time for the α -particle would be
A uniform magnetic field B is acting from south to north and is of magnitude 1.5 Wb/m 2 . If a proton having mass = 1.7 × 10 − 27 kg and charge = 1.6 × 10 − 19 C moves in this field vertically downwards with energy 5 Me V, then the force acting on it will be
An α -particle travels in a circular path of radius 0.45 m in a magnetic field B = 1.2 Wb/m 2 with a speed of 2.6 × 10 7 m / s . The period of revolution of the α -particle
A battery is connected between two points A and B on the circumference of a uniform conducting ring of radius r and resistance R. One of the arcs AB of the ring subtends an angle θ at the centre. The value of the magnetic induction at the centre due to the current in the ring is
A proton, a deuteron and an a-particle having the same kinetic energy are moving in circular trajectories in a constant magnetic field. If r p , r d and r α denote, respectively, the radii of the trajectories of these particles, then
A proton (mass = 1.67 × 10 − 27 kg and charge = 1.6 × 10 − 19 C is projected in a uniform magnetic field of 2 Wb/m 2 with a velocity 3.4 × 10 7 m / s in a direction perpendicular to the field. The acceleration of the proton should be
Two straight horizontal parallel wires are carrying the same current in the same direction. d is the distance between the wires. You are provided with a small freely suspended magnetic needle. At which of the following positions will the orientation of the needle be independent of the magnitude of the current in the wires?
A charged particle moving at an angle 30 0 with an uniform magnetic field of 0.5 tesla. If the velocity of the charged particle is 10 m/s and its charge is 2C then force acting on it is
A long, straight, hollow conductor tube carrying a current has two sections A and C of unequal cross section joined by a conical section B. 1, 2 and 3 are the points on a line parallel to the axis of the conductor. The magnetic fields at 1, 2 and 3 have magnitude B 1 , B 2 and B 3 :
A current element of length d l and carrying current I in Z direction is placed at (1, 1, 0). Let magnetic field at origin be B 1 and at point (2, 2, 0) be B 2 , then which of the following is correct?
A current flows along the length of an infinitely long, straight and thin-walled pipe. Then
A vertical wire carries a current in upward direction. If an electron beam sent horizontally towards the wire, then it will deflected
A current I flowing through the loop as shown in figure. The magnetic field at centre O is :
Through two parallel wires and B, 10 and 2 ampere of currents are passed respectively in opposite direction. If the wire A is infinitely long and the length of the wire B is 2 m, the force on the conductor B, which is situated at 10 cm distance from A will be :
A toroidal solenoid has 3000 turns and a mean radius of 10 cm. It has a soft iron core of relative permeability 2000. What is the magnitude of the magnetic field in the core when a current of 1 amp is passed through the solenoid ?
A tangent galvanometer has a coil with 50 turns and radius equal to 4 cm. A current of 0.1 amp is passing through it. The plane of the coil is set parallel to the earth’s magnetic meridian. If the value of the earth’s horizontal component of the magnetic field is 7x 10 -5 Tesla and μ 0 = 4 π × 10 − 7 weber/amp’ x metre, then the deflection in the galvanometer needle will be
Two particles each of mass m and charge q are attached to two ends of a light rod of length 2l. The rod is rotated at a constant angular speed about a perpendicular axis passing through its centre. The ratio of the magnitudes of the magnetic moment of the system to its angular momentum will be
A length of wire caries a steady current. First it is bent to form a circular coil of one tum. Then it is bent more sharply to form a loop of two turns but of smaller radius. Now the magnetic flux density at the centre caused by same current is found to be such that
A vertical straight conductor carries a current vertically upwards. A point P lies to the east of it a small distance and another point Q lies to the west at the same distance. The magnetic field at P due to the current carrying conductor is
A portion of a conductive wire is bent in the form of a semicircle of radius r as shown below in fig. At the centre of semicircle, the magnetic induction will be
What is the magnetic field at O due to current in the B infinite wire forming a loop as shown in fig. ?
A cument is passed in an equilateral triangle of side l and made of a uniform conducting wire as shown in fig. The magnetic induction at centre O will be
What will be the magnitude of magnetic induction at the centre oi a square loop of side l, if a current i is flowing in the loop ?
An electron-beam passes through a magnetic field B of 2×10 -3 Weber/m 2 and an electric field E of 3.4×10 4 volt / met re acting simultaneously. If the path of the electron remains undeviated, the speed of the electron will be
A current i is flowing in a hexagonal coil of side / [Fig.]. The magnetic induction at the centre of the coil will be
A long wire is bent into shape ABCDE as shown in fig. with BCD being a semicircle with centre O and radius r metre. A current of I amp flows through it in the direction A B C D E. Then the magnetic induction at the point O of the figure in vacuum is
Two circular coils X and Y having equal number of turns and carry equal currents in the same sense and subtend same solid angle at point O. If the smaller coil X is midway between O and Y, then if we represent the magnetic induction due to bigger coil Y at O as B Y and due to smaller coil X at O as B X , then
A and B. are two centric circular conductor of centre O and carrying currents i 1 and i 2 , as shown in fig. The ratio of their radii is 1:2 and ratio of the flux densities at O due to A and B is 1 :3. The value of i 1 , / i, 2 will be
A current i amp flows along an infinitely long straight thin walled tube, then the magnetic induction at any point inside the tube is
The magnetic field due to a straight conductor of uniform cross-section of radius a and carrying a steady current is represented by
Two wire loops PQRSP formed by joining two semicircular wires of radii -R 1 , and R 2 , carries a current as shown in fig. The magnitude of the magnetic induction at the centre C is
The field normal to the plane of a wire of n turns and radius r which carries a current i is measured on the axis of the coil at a small distance h from the centre of the coil. This is smaller than the field at the centre by the fraction
A circular current carrying coil has a radius .R. The distance from the centre of the coil, on the axis where the magnetic induction will be 1/8th to its value at the centre of the coil is
A long wire carries a current of 20 A along the axis of solenoid. The field due to the solenoid is 4 mT. The resultant field at a point 3 mm from the solenoid axis is
A long wire carries a steady Current. It is bent into a circle of one turn and the magnetic field at the centre of the coil is B. It is then bent into a circular loop of n turns. The magnetic field at the centre of the coil will be
A solenoid of 1 . 5 metre length and 4 .0 cm diameter possesses 10 turns per cm. A current of 5 ampere is flowing through it. The magnetic field at axis inside the solenoid is (Given: μ 0 = 4 π × 10 − 7 weber/amp metre)
The magnetic field due to a current carrying circular loop of radius 3 cm at a point on the axis at a distance of 4 cm from the centre is 54 μ T, What will be the value at the centre of the loop
An electron of charge e moves in a circular orbit of radius r around a nucleus. The magnetic field due to orbital motion of the electron at the site of the nucleus is B. The angular velocity ω of the electron is
An electron is revolving around a proton in a circular orbit of diameter 1 Å . If it produces a magnetic field of 14 weber/m 2 at the proton, then its angular velocity will be about
An electron (mass = 9×10 -31 kg, charge = 1.6 x 10 -19 C) moving with a velocity of 10 6 m/s enters a region where magnetic field exists. If it describes a circle of radius 0.10m, the intensity of the magnetic field must be
Through two parallel wires A and B, 10 and 2 amp of currents are passed respectively in opposite directions. If the wire A is infinitely long and the length of the wire B is 2 m, the force on the conductor 8, which is situated at 10 cm distance from A, will be
Two long parallel wires separated by a distance d have equal current i flowing in each. The magnetic field of one exerts a force F on the other. The distance d is increased to 2 d and current in each wire is reduced from i to i / 2 What is the force between them now ?
Consider three long, straight, parallel wires shown in fig. The force experienced by 25 cm length of wire C is
Two long parallel wires P and Q are held perpendicular to the plane of paper with distance of 5 m between them. If P and Q carry current of 2.5 amp and 5 amp respectively in the same direction, then the magnetic field at a point half-way between the wires is
A charge particle of mass m and charge g travels on a circular path of radius r that is perpendicular to the magnetic. field B. The time taken by the particle to complete one revolution is
An electron with a speed u along the positive x-axis at y = 0 enters a region of uniform magnetic field B= -B o k which exists to the right of y-axis. [Fig.] The electron exists from the region after some time with the speed v at ordinate y, then
An electron is shot in steady electric and magnetic fields such that its velocity v, electric field E and magnetic field B are mutually perpendicular. The magnitude of E is 1volt/ cm and that of B is 2 tesla. Now it so happens that the Lorentz (magnetic) force cancels the electrostatic force on the electron, then the velocity of electron is
A magnetic field of induction 8= 35.34×10 -6 T is applied on an electron in a direction perpendicular to its motion. Find the time required for the electron to complete one revolution. Assume its mass and charge
A 2 MeV proton is moving perpendicular to a uniform magnetic field 2 .5 T. The force on the proton is
AIfa particles (m= 6.7×10 -27 kg and q = 2e) arc accelerated from rest through a potential difference of 6 . 7 kV. Then they enter a magnetic field B = 0 .2 T perpendicular to their direction of motion. The radius of the path described by them is
In a region, steady and uniform electric and magnetic fields are present. These two fields are parallel to each other. A charged particle is released from rest in this region. The path of the particle wiII be
The two particles X and Y, having equal charge, after being accelerated through the same potential difference, enter a region of uniform magnetic field and describe circular paths of radii R 1 and R 2 respectively. The ratio of the mass of X to that of Y is
A particle of charge -16 x10 -18 C moving with velocity 10 m/s along the X-axis enters a region where a magnetic field of induction B is along Y-axis and electric field of magnitude 104 V/m is a. long the negative Z-axis. If the charged particle continues moving along the X-axis, the magnitude of B is
A particle of charge + q and mass m moving under the influence of a uniform electric field E i and a uniform magnetic field B k follows trajectory from P to Q as shown in fig. The velocities at P and Q are v i and – 2 v j respectively. Which of the following statements (s) is/are correct
A beam of ions with velocit5r 2×10 5 m/sec enters normally into a uniform magnetic field of 4 x10 -2 tesla. If the specific charge of the ion is 5 x 10 7 C/kg, the radius of the circular path described will be
An electron of mass 0.90 x 10 -30 kg under the action of magnetic field moves in a circle of radius 2.0 cm at a speed of 3.0 x 10 6 m/sec. If a proton of mass 1.8 x 10 -27 kg were to move in a circle of the same radius in the same magnetic field, then its speed will be
A proton enters a magnetic field with a velocity of 2.5 x 10 7 m/s making angle 30° with the magnetic field. What is the force on the proton ? (Given B = 2.5T)
An electron moving with kinetic energy 6.6 x 10 -14 J enters a magnetic field 4 X10 -3 T at right angle to it, The radius of circular path will be nearest to
A beam of electrons is moving with constant velocity in a region having electric and magnetic fields of strength 20 Vm -1 and 0.5 T at right angles to the direction of motion of the electrons. What is the velocity of the electrons ?
A galvanometer of resistance 200 Ω gives a full scale deflection for a current of10 -3 A. To convert it into an ammeter capable of measuring up to 1 A, what resistance should be connected in parallel with it ?
A galvanometer of resistance 200 Ω gives full scale deflection with 15 milli-ampere current. In order to convert it into a 15 V range voltmeter, the value of resistance connected in series is
The seave of a galvanometer of resistance 100 Ω contains 25 divisions. It gives a deflection of 1 division on passing a current of 4 x 10 -4 A. The resistance in ohm to be added to it, so that it may become a voltmeter of range 2 .5 V is
The range of a voltmeter of resistance G ohm is V volt. The resistance required to be connected in series with it in order to convert it into voltmeter of range n V volt will be
A charged particle with charge g enters a region of constant, uniform and mutually orthogonal fields E and B with a velocity v perpendicular to both E and B and comes out without any change in magnitude or direction of v. Then
A microammeter has a resistance of 100 Ω and a full scale range of 50 μ A. It can be used as a voltmeter or as a higher range ammeter provided a resistance is added to it. Pick the correct range and resistance combination(s).
For a positively charged particle moving in X-Y plane initially along the X-axis, there is a sudden change in its path due to the presence of electric and/or magnetic fields beyond P as shown in fig. The curved path is shown in X-Y plane and is found to be non-circular. Which one of the following combinations is possible ?
Two circular coils P and Q are made from similar wires but radius of Q is twice that of P. What should be the value of potential difference across them so that the magnetic induction at their centre may be the same ?
A conducting loop carrying a current i is placed in a uniform magnetic field acting perpendicular to the plane of the coil as shown in fig. The loop will have a tendency to
A long straight wire of radius a carries a steady current i. The current is uniformly distributed across its cross section. The ratio of the magnetic field at a /2and 2a is
An electron accelerated through a potential difference y enters into a uniform transverse magnetic field and experiences a force F. If the accelerating potential increases to 2V, the electron in the same magnetic field will experience a force :
A circular coil has one turn and carries a current i. The same wire is wound into a smaller coil of 4 turns and the same current is passed through it. The field at the centre
A charged particle moving in a uniform magnetic field penetrates a layer of lead and loses one half of its kinetic energy. The radius of curvature changes to
A current of 10 amp is flowing in a wire of length 1 .5 metre. A force of 15 newton acts on it when it is placed in a uniform magnetic field of 2 tesla. The angle between the magnetic field and the direction of current is
A uniform magnetic field is at right angle to the direction of motion of protons. As a result, the protons describe a circular path of radius 2 .5 cm. If the speed of the protons is doubled, then the radius of the circular path will be
Two straight long conductors AOB and, COD are perpendicular to each other and carry currents i 1 , and i 2 . The magnitude of the magnetic induction at a point P at a distance d from the point O in a direction perpendicular to the plane, ABCD is
In fig. two long parallel wires carry equal currents in opposite directions. Point O is situated midway between the wires and the X-Y plane contains the two wires and the positive Z-axis comes normally out of the plane of paper. The magnetic field B at O is non-zero along
The magnetic field at the center O of the circular portion of the current carrying wire [Fig.]
Two long parallel wires carry equal current in the same direction. The length of each wire is l and the distance between them is d. Force acting on each wire
A long wire carries a current of 20 A along the axis of a solenoid. The field due to the solenoid is 4 mT. The resultant field at a point 3 mm from the solenoid axis is
A wire of length I metre carrying a current i ampere is bent in the form of a circle. The magnitude of magnetic moment is
A charged particle is released from rest in a region of steady and uniform electric and magnetic fields which are parallel to each other. The particle will move in a
A proton, a deuteron and an α -particle having the same kinetic energy are moving in circular trajectories in a constant magnetic field lf r p ,r d and r α denote respectively the radii o[ the trajectories of these particles, then
A coil of wire having inductance and resistance has a conducting ring placed coaxially within it The coil is connected to a battery at time t = 0′ so that a time-dependent current i (t) starts flowing through the coil: If i 2 (t) is the magnetic field at the axis of the coil due to i 1 (t) then as a function of time (t >0)’ the product i 2 (t) B(t)
A uniform magnetic field with a slit system as shown in fig.is to be used as a momentum filter for high-energy charged particles’ With a field B tesla’ it is found that the filter transmits α -particles each of energy 5 3 MeV. The magnetic field is increased to 2.3 B tesla and deuterons are passed into the filter’ The energy of each deuteron transmitted by the filter is
Two particles A and B of masses m A and. m B respectively and having the same charge are moving in a plane. A uniform magnetic field exists perpendicular to this plane. The speeds of the particles are v A and v B respectively and trajectories are as shown in fig Then
A particle of mass m and charge q moves with a constant velocity v along the positive x direction’ It enters a region containing a uniform magnetic field B directed along the negative Z-direction, extending from x = a to x = b. The minimum value of v required so that the particle can just enter the region x >b is
A long straight wire along the Z-axis carries a current i in the negative Z-direction. The magnetic vector field B at a point having coordinates (x, y) in the Z = 0 plane is
An ammeter is obtained by shunting a 30 Ω galvanometer with a 30 Ω resistance. What additional shunt should be connected across it to double the range ?
A voltmeter with a resistance of 50 x10 3 ohm is used to measure voltage in a circuit. To increase its range to 3 times, the additional resistance to be put in series is
A galvanometer, having a resistance of 50 Ω , gives a full sale deflection for a current of 0.05 A. The length in metre of a resistance wire of area of cross-section 2.97x 10 -6 cm 2 that can be used to convert the galvanometer into an ammeter which can read a maximum of 5 A current is (specific resistance of the wire = 5 x 10 -7 Ω m)
The seave of a galvanometer of resistance 100 Ω contains 25 division. It gives a deflection of one division on passing a current of 4 x 10 -4 a ampere. The resistance in ohm to be added to it, so that it may become a voltmeter of range 2.5 volt is
The resistance of a moving coil galvanometer is 10 Ω and gives a full scale deflection for a current 5 mA The series resistance required to convert it into a voltmeter to read maximum 100 volt is
A galvanometer of 50 ohm resistance has 25 divisions ‘A current of 4x 10 -4 ampere gives a deflection of one division. To convert this galvanometer into a volt metre having a range of 25 volts, it should be connected with a resistance of
