The insulation property of air breaks down at E= 3x 10 6 volt per metre. The maximum charge that can be given to a sphere of diameter 5 metres is approximately
Two conducting spheres each of radius R carry charge q. They are placed at a distance r from each other, where r > > 2R. The neutral point lies at a distance r/2 from either sphere. If the electric field at the neutral point due to either sphere be E, then the total electric potential at that point will be
A given charge is situated at a certain distance from an electric dipole in the end-on position, experiences a force F. If the distance of the charge is doubled, the force acting on the charge will be
Three particles have charges + 20 μ C each and they are fixed at the comers of a:r equilateral triangle of side 0.5 m. The force on each of the particles has magnitude
A charge g is placed at the centre of the line joining the equal charges Q. The system of three charges will be in equilibrium if q is equal to
A spherical charged conductor has σ as the surface density of charge. The electric field on its surface is E. If the radius of the sphere is doubled keeping the surface density of charge unchanged, what will be the electric field on the surface of the new sphere ?
There are n electrons on a drop of oil. It is in equilibrium in an electric field of intensity E. If the density of the oil is ρ , then radius of the drop will be
Five point charges, each of + q coulomb are situated at the vertices of a regular hexagon of side / metre Fig. The resultant force on charge – q placed at the centre of the hexagon will be
Charge q is divided in two parts q 1 and q 2 and these are placed at a distance r. For maximum repulsion between these parts
Due to the dipole shown in the fig , the electric intensity will be parallel or antiparallel to the dipole at the point
A charge of 6 . 75 μC in an electric field is acted upon by a force of 2.5 N. The potential gradient at this point is
A uniformly charged conducting sphere of 2.4 m diameter has a surface charge density of 80 μC / m 2 . The total electric flux leaving the surface of the sphere is
The length of each side of a cubical closed surface is l. If charge q is situated on one of the vertices of the cube, then the flux passing through each face of the cube will be
The electric potential at a certain distance from a source charge is 600 V and electric field strength at that point is 150 N/C. What is the distance of observation point from the source charge ?
The electric strength of air is 2.0 x 10 6 N/C. The largest charge that a metallic sphere of 3 mm radius can hold is
Two point charges of 20 μC and 80 μC are 10 cm apart. Where will the electric field strength be zero on the line joining the charges ?
Two small balls, each carrying a charge q are suspended by equal insulated strings of length / m from the hook of a stand. This arrangement is carried in a satellite in space. The tension in each string will be
The ratio of electric fields due to an electric dipole at equal distances in its axial and equatorial position will be
A circular ring carries a uniformly distributed positive charge and lies in X-Y plane with centre at origin of coordinate system. If at a point (0,0, z), the potential is V, then which of the following graphs Fig is correct ?
An electric dipole, consisting of two opposite charges of 2 x 10 -6 C each separated by a distance of 3 cm is placed in an electric field of 2 x 10 5 newton per coulomb. The maximum torque on the dipole will be
An electric dipole consists of two opposite charges each of magnitude 1.0 x 10 -6 coulomb separated by a distance 2.0 cm. The dipole is placed in an external field of 1.0 x 10 5 N/coul. The maximum torque on the dipole is
Two identical metal balls with charges + 2 Q and -Q are separated by some distance and exert a force F on each other. They are joined by a conducting wire, which is than removed. The force between them will now be
Six charges, three positive and three negative of equal magnitude are to be placed at the vertices of a regular hexagon such that the electric field at O is double the electric field when only one positive charge of same magnitude is placed at ft. Which of the following arrangements of charges is possible for P, Q, R, S, T and U respectively ?
The potential at a point x (measured in μ m) due to some charges situated on the X-axis is given by V ( x ) = 20 / x 2 − 4 volt. The electric field E at x = 4 μ m is given by
How does the electrical field strength vary when we enter a uniformly charged spherical cloud ?
Two particles of masses m and 2 m with charges 2q and 2q are placed in a uniform electric field E and allowed to move for the same time. The ratio of their kinetic ener8ies will be
The variation of electric field intensity (E) with distance from centre of uniformly charged spherical shell is best represented by which of the following graphs ?
Two point charges + I q and -2 q are located at x = 0 and x = 1 respectively. The location of a point on the X-axis at which the net electric field due to these two point charges is zero is
The inward and outward electric flux from a closed surface are respectively 8 x 10 3 and 4 x 10 3 units. Then the net charge inside the closed surface is
