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By rohit.pandey1
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Updated on 2 Jul 2026, 18:19 IST
Magnetic Effects of Electric Current Class 10 Notes explain how electric current produces a magnetic field and how this magnetic field is used in devices such as electromagnets, electric motors, domestic circuits, and safety devices. This chapter connects two important ideas: electricity and magnetism.
In the latest CBSE Class 10 Science Syllabus, this chapter is Chapter 12: Magnetic Effects of Electric Current. CBSE includes this topic under Unit IV: Effects of Current, which carries 13 marks in the Class 10 Science theory paper. The official CBSE syllabus includes magnetic field, magnetic field lines, field due to a current-carrying conductor, coil and solenoid, force on a current-carrying conductor, Fleming’s left-hand rule, direct current, alternating current, frequency of AC, advantage of AC over DC, and domestic electric circuits.
This chapter covers the magnetic effect produced by electric current. When current flows through a conductor, it behaves like a magnet and produces a magnetic field around it. NCERT introduces this idea through Oersted’s experiment, where a compass needle gets deflected near a current-carrying wire. This shows that electricity and magnetism are related.
| Particular | Details |
| Class | 10 |
| Subject | Science |
| Branch | Physics |
| Chapter Name | Magnetic Effects of Electric Current |
| Current NCERT Chapter Number | Chapter 12 |
| Common Older Search Name | Chapter 13 |
| CBSE Unit | Unit IV: Effects of Current |
| Important For | Board exams, school exams, diagrams, MCQs and case-study questions |
| Main Topics | Magnetic field, field lines, right-hand thumb rule, solenoid, electromagnet, Fleming’s left-hand rule, AC, DC, domestic circuit |
A magnetic field is the region around a magnet where magnetic force can be experienced.
For example, when a compass needle is brought near a bar magnet, the needle gets deflected. This happens because the magnet produces a magnetic field around itself.
NCERT explains that the region surrounding a magnet where magnetic force can be detected is called a magnetic field, and iron filings arrange themselves along magnetic field lines around a bar magnet.
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Magnetic field lines are imaginary lines used to represent the magnetic field around a magnet.
They show:
Outside the magnet, magnetic field lines move from the north pole to the south pole.
Inside the magnet, field lines move from the south pole to the north pole.
Therefore, magnetic field lines are closed curves. NCERT states that outside a magnet, field lines emerge from the north pole and merge at the south pole, while inside the magnet they go from south to north.
Magnetic field lines never intersect each other because if they intersected, a compass needle placed at the point of intersection would point in two different directions at the same time. This is not possible.
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So, magnetic field lines cannot cross each other.
Oersted’s experiment shows that an electric current produces a magnetic field.
A straight copper wire is placed near a compass needle. When current is passed through the wire, the compass needle gets deflected.
The compass needle changes its direction when electric current flows through the wire.
An electric current-carrying conductor produces a magnetic field around it.
NCERT explains that when current passes through a metallic conductor near a compass, the compass needle gets deflected. This proves that electric current produces a magnetic effect.
Image alt text: Oersted experiment Class 10 showing compass deflection near current carrying wire.
When electric current flows through a straight conductor, magnetic field lines are formed around it in the form of concentric circles.
The centre of these circles lies on the conductor.
NCERT explains that the field around a straight current-carrying wire appears as concentric circles and that magnetic field strength increases with current but decreases with distance from the wire.
The right-hand thumb rule is used to find the direction of magnetic field around a current-carrying conductor.
If you hold a current-carrying straight conductor in your right hand such that your thumb points in the direction of current, then your curled fingers show the direction of magnetic field lines.
This rule is also called Maxwell’s corkscrew rule.
When current flows through a circular loop, magnetic field lines are formed around the loop.
At the centre of the circular loop, magnetic field lines become almost straight and are perpendicular to the plane of the loop.
NCERT explains that for a circular coil having n turns, the magnetic field produced is n times that produced by a single turn because the field due to each turn adds up. (NCERT)
A solenoid is a coil of many circular turns of insulated copper wire wound closely in the shape of a cylinder.
When current flows through a solenoid, it behaves like a bar magnet.
NCERT states that the magnetic field pattern around a current-carrying solenoid is similar to that of a bar magnet, and that the field inside a solenoid is uniform because field lines are parallel straight lines.
An electromagnet is a temporary magnet produced by passing electric current through a coil wound around a soft iron core.
An electromagnet is made using:
When current flows through the coil, the soft iron core becomes magnetised and behaves like a magnet.
When current is switched off, the soft iron core loses most of its magnetism.
| Permanent Magnet | Electromagnet |
| It is always magnetic. | It becomes magnetic only when current flows. |
| Strength is usually fixed. | Strength can be changed by changing current. |
| Polarity is fixed. | Polarity can be reversed by reversing current. |
| Usually made of steel or magnetic alloys. | Usually made using soft iron core and coil. |
| Used in compass, speakers, fridge magnets. | Used in electric bells, cranes and relays. |
A current-carrying conductor placed in a magnetic field experiences a force.
This force depends on:
NCERT explains that a magnetic field exerts force on a current-carrying conductor, and the direction of force depends on the direction of current and magnetic field. (NCERT)
Fleming’s left-hand rule is used to find the direction of force on a current-carrying conductor placed in a magnetic field.
Stretch the thumb, forefinger and middle finger of your left hand so that they are mutually perpendicular to each other.
Then:
FBI
| Letter | Meaning |
| F | Force |
| B | Magnetic field |
| I | Current |
CBSE includes direct current, alternating current, frequency of AC and advantage of AC over DC in the official Class 10 Science syllabus.
Direct current, or DC, is the current that flows in one direction only.
Alternating current, or AC, is the current that changes direction periodically.
| AC | DC |
| Full form is alternating current. | Full form is direct current. |
| Direction changes periodically. | Direction remains the same. |
| Used in household supply. | Used in cells and batteries. |
| Can be transmitted over long distances more easily. | Less suitable for long-distance transmission. |
| In India, AC frequency is 50 Hz. | Frequency of DC is zero. |
The frequency of AC in India is 50 Hz.
This means the current changes direction 50 times per second.
AC is preferred over DC for domestic and long-distance transmission because:
A domestic electric circuit is the wiring system used in homes to supply electricity to appliances.
In domestic circuits, appliances are generally connected in parallel so that each appliance gets the same voltage and can be switched on or off independently.
| Wire | Common Colour | Function |
| Live wire | Red/Brown | Carries current from supply to appliance |
| Neutral wire | Black/Blue | Completes the circuit |
| Earth wire | Green/Yellow-green | Safety wire connected to metallic body of appliance |
NCERT’s domestic circuit section explains household wiring using live, neutral and earth wires, and CBSE specifically includes domestic electric circuits in this chapter’s syllabus.
Image alt text: Domestic electric circuit Class 10 live neutral earth wire diagram.
A short circuit occurs when the live wire and neutral wire come into direct contact.
This causes a sudden increase in current.
Overloading occurs when too many appliances are connected to the same circuit or when appliances draw more current than the circuit can safely handle.
| Short Circuit | Overloading |
| Live and neutral wires touch directly. | Too many appliances draw excessive current. |
| Current rises suddenly. | Current increases beyond safe limit. |
| Usually caused by damaged insulation or loose contact. | Usually caused by excessive load. |
| Fuse melts or MCB trips. | Fuse melts or MCB trips. |
An electric fuse is a safety device used to protect electrical circuits from excessive current.
It is made of a wire with low melting point.
When excessive current flows through the circuit, the fuse wire becomes hot and melts. This breaks the circuit and stops the flow of current.
Earthing is a safety measure in which the metallic body of an electrical appliance is connected to the earth through an earth wire.
If the live wire accidentally touches the metallic body of an appliance, the current flows safely to the earth through the earth wire. This prevents electric shock.
This chapter is very diagram-based. Students should practise these diagrams:
This chapter has fewer numerical formulas than Electricity, but the following rules and values are very important.
| Rule/Value | Use |
| Right-hand thumb rule | Direction of magnetic field around current-carrying conductor |
| Fleming’s left-hand rule | Direction of force on current-carrying conductor |
| AC frequency in India | 50 Hz |
| Domestic supply voltage in India | About 220 V |
| Solenoid field | Strong and uniform inside solenoid |
| Current in coil with n turns | Field becomes n times stronger than single turn |
| Force condition | Maximum when current is perpendicular to magnetic field |
| Mistake | Correct Understanding |
| Confusing right-hand thumb rule with Fleming’s left-hand rule | Right-hand thumb rule gives magnetic field direction; Fleming’s left-hand rule gives force direction. |
| Drawing magnetic field lines crossing each other | Magnetic field lines never intersect. |
| Saying field lines exist only outside a magnet | Field lines form closed curves and also exist inside the magnet. |
| Confusing AC and DC | AC changes direction; DC flows in one direction. |
| Saying fuse is connected in parallel | Fuse is connected in series with live wire. |
| Confusing short circuit and overloading | Short circuit is direct contact of live and neutral; overloading is excessive current due to high load. |
| Forgetting earth wire function | Earth wire protects from electric shock. |
| Drawing solenoid field randomly | Field lines inside a solenoid are parallel and uniform. |
A. current produces heat
B. current produces magnetic field
C. current produces light
D. current produces sound
Answer: B. current produces magnetic field
A. south to north
B. north to south
C. east to west
D. west to east
Answer: B. north to south
A. they are straight lines
B. they are circular lines
C. a compass cannot point in two directions at the same point
D. magnets do not have poles
Answer: C. a compass cannot point in two directions at the same point
A. straight lines
B. concentric circles
C. parallel lines
D. zig-zag lines
Answer: B. concentric circles
A. electric current
B. magnetic field
C. electric force
D. gravitational force
Answer: B. magnetic field
A. a glass rod
B. a bar magnet
C. a resistor
D. an insulator
Answer: B. a bar magnet
A. circular
B. random
C. parallel straight lines
D. absent
Answer: C. parallel straight lines
A. force on a current-carrying conductor
B. electric field
C. resistance
D. heat produced
Answer: A. force on a current-carrying conductor
A. 20 Hz
B. 40 Hz
C. 50 Hz
D. 100 Hz
Answer: C. 50 Hz
A. parallel with neutral wire
B. series with live wire
C. parallel with earth wire
D. series with earth wire
Answer: B. series with live wire
Assertion: Magnetic field lines never intersect each other.
Reason: At the point of intersection, a compass needle would have to point in two directions.
Answer: Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
Assertion: A solenoid behaves like a bar magnet when current flows through it.
Reason: A current-carrying solenoid produces a magnetic field similar to that of a bar magnet.
Answer: Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
Assertion: Fuse is connected in series with the live wire.
Reason: Fuse must stop the current when excessive current flows.
Answer: Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
Assertion: AC is preferred for long-distance transmission.
Reason: AC voltage can be easily changed using transformers.
Answer: Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
Read the passage and answer the questions.
A student places a straight copper wire near a compass needle. When the key is inserted and current flows through the wire, the compass needle gets deflected. When the direction of current is reversed, the needle deflects in the opposite direction.
Magnetic Effects of Electric Current Class 10 Notes are important for understanding how electricity and magnetism are connected. This chapter explains magnetic field, magnetic field lines, Oersted’s experiment, magnetic field due to current-carrying conductors, right-hand thumb rule, circular loop, solenoid, electromagnet, force on a current-carrying conductor, Fleming’s left-hand rule, AC, DC and domestic electric circuits.
For exam preparation, students should focus on diagrams, rules, definitions, differences, safety devices, domestic circuits, MCQs and case-study questions. This chapter is highly scoring if students practise the diagrams and understand the direction-based rules clearly.
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The magnetic effect of electric current means that a current-carrying conductor produces a magnetic field around it. This was demonstrated by Oersted's experiment.
Hans Christian Oersted discovered it in 1820. He observed that a compass needle gets deflected when placed near a wire carrying electric current, proving that electric current produces a magnetic field.
A magnetic field is the region around a magnet or a current-carrying conductor where its magnetic effect can be experienced.
Magnetic field lines are imaginary lines that represent the magnetic field around a magnet. They emerge from the north pole and enter the south pole outside the magnet, and show the direction (tangent at any point) and relative strength (closer lines = stronger field) of the magnetic field.
Magnetic field lines do not intersect each other because at any given point there can be only one direction of the magnetic field. If two lines intersected, it would mean the field has two directions at that point, which is impossible.
If a straight current-carrying conductor is held in the right hand such that the thumb points in the direction of current flow, then the curled fingers indicate the direction of the magnetic field lines around the conductor.
A solenoid is a coil consisting of many circular turns of insulated copper wire wound closely in the form of a cylinder. When current flows through it, it behaves like a bar magnet and produces a strong uniform magnetic field inside it.
A current-carrying solenoid produces a magnetic field similar to that of a bar magnet — with one end acting as the north pole and the other as the south pole. The field lines outside are identical to a bar magnet and the field inside is strong and uniform. The polarity depends on the direction of current.
An electromagnet is a temporary magnet made by winding a coil of insulated copper wire around a soft iron core and passing electric current through it. It loses its magnetism when the current is switched off. Soft iron is used as the core because it is easily magnetised and demagnetised.
If the left hand is stretched such that the index finger, middle finger and thumb are mutually perpendicular — the index finger points in the direction of the magnetic field (B), the middle finger points in the direction of current (I), then the thumb points in the direction of the force (motion) on the conductor.
Direct current (DC) flows in one direction only and maintains constant polarity (e.g., from a battery). Alternating current (AC) periodically reverses its direction of flow. AC is used for domestic supply because it can be transmitted over long distances with less energy loss and its voltage can be stepped up or down using transformers.
The frequency of AC in India is 50 Hz, meaning the current completes 50 cycles per second and changes direction 100 times per second.
A domestic electric circuit is the wiring arrangement used in homes to distribute electricity. It consists of three wires — the live wire (red/brown, at 220V), the neutral wire (black/blue, at 0V), and the earth wire (green/yellow) for safety. Appliances are connected in parallel so each gets the same voltage and can be operated independently.
A short circuit occurs when the live wire and the neutral wire come into direct contact due to damaged insulation or faulty wiring, resulting in a sudden, drastic drop in resistance and a very large current flowing through the circuit, which can cause fire or damage.
Overloading occurs when too many high-power electrical appliances are connected to a single circuit and draw more current than the circuit wires are designed to carry safely, causing excessive heating of wires.
A fuse is a safety device made of a thin wire of low melting point alloy (tin-lead). When the current exceeds the safe limit due to short circuit or overloading, the fuse wire heats up and melts, breaking the circuit and protecting the wiring and appliances from damage.
Earthing is a safety measure in which the metal body of an electrical appliance is connected to the earth through a wire. If a fault causes the live wire to touch the metal body, the current flows harmlessly into the earth instead of passing through the user's body, preventing electric shock.
The important diagrams are: magnetic field lines around a bar magnet, Oersted's experiment setup, magnetic field around a straight current-carrying conductor (right-hand thumb rule), magnetic field due to a circular loop, magnetic field of a solenoid, an electromagnet, Fleming's left-hand rule (hand diagram), and a domestic electric circuit with live, neutral and earth wires.