Magnetic Effects of Electric Current — Class 10 Science PYQs

10 previous-year board questions (2026) with marking-scheme solutions, grouped by topic and marks.

Try each question first, then press ↓ (or tap Show Solution) to reveal the answer. Press ↓ again for the next question.

Marks:

Magnetic field and field lines

1 Mark Questions
11 Mark · March 2026 · Standardopen ↗
Assertion (A) : The needle of a magnetic compass kept in strong external magnetic field, always aligns itself in north south direction on the earth.
Reason (R) : Behaviour of the needle of a compass is same as that of a freely suspended bar magnet.
  • (a)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
  • (b)Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
  • (c)Assertion (A) is true, but Reason (R) is false.
  • (d)Assertion (A) is false, but Reason (R) is true.
Show SolutionHide Solution↓
(D)/Assertion (A) is false but Reason (R) is true. (1 Mark)

Field due to conductor, loop, and solenoid

2 Marks Questions
22 Marks · March 2026 · Standardopen ↗
How is an electromagnet made ? Write any two ways by which the strength of electromagnet can be increased.
Show SolutionHide Solution↓
• An electromagnet is formed by wrapping a current carrying insulated copper wire in the form of coil around a magnetic material like soft iron core. / By placing a magnetic material like soft iron as a core material inside the current carrying solenoid. (1 Mark)
• Strength of electromagnet can be increased by increasing the
(i) Number of turns of coil (½ Mark)
(ii) Current flowing through the coil. (½ Mark)
3 Marks Questions
33 Marks · March 2026 · Standardopen ↗
The pattern of magnetic field due to a current carrying wire depends upon the shape made by that wire. Justify.
Show SolutionHide Solution↓
Solution not available.
4 Marks Questions
44 Marks · March 2026 · Standardopen ↗
Read the following passage and answer the questions that follow :
H.C. Oersted demonstrated that every current-carrying wire produces magnetic field around it. The pattern of the magnetic field depends upon the geometrical structure the current carrying wire is folded into. When a current-carrying wire is kept in a magnetic field, it experiences a force. Magnitude of this force is maximum when direction of magnetic field is at right angles to the current-carrying wire. Some rules to determine the direction of magnetic field and force were given by scientists Maxwell and Fleming.
(a) What is the direction of magnetic field inside and outside a solenoid?
(b) Same electric current is flowing through three identical wires A, B and C. If wires A, B and C are making respectively angles $\text{30\degree}$, $\text{60\degree}$ and $\text{270\degree}$ with the magnetic field, which of the wires will experience maximum force and why ?
(c) (i) Name and state the law which is required to find out the direction of force acting on a current carrying wire, kept in a magnetic field.
OR
(c) (ii) Name and state the law which is required to find out the direction of magnetic field around the current carrying straight conductor.
Show SolutionHide Solution↓
(a) • Inside - from south pole to north pole (½ Mark)
• Outside - from north pole to south pole (½ Mark)
(b) • Wire - C (½ Mark)
• As wire -C is making angle of $90^\circ$ ($360^\circ-270^\circ$) with magnetic field. (½ Mark)
(c) (i) • Fleming's left-hand rule (1 Mark)
• Stretch the thumb, fore finger and middle finger of your left hand such that they are mutually perpendicular. If first finger points the direction of magnetic field and second finger in the direction of current then the thumb will point in the direction of motion or force on the conductor. (1 Mark)
(c) (ii) • Right hand thumb rule (1 Mark)
• Imagine that you are holding a current carrying straight conductor in your right hand such that the thumb points towards the direction of current. Then your fingers wrap around the conductor in the direction of field lines of magnetic field. (1 Mark)

Force on a conductor; Fleming's Left-Hand Rule; electric motor

1 Mark Questions
51 Mark · March 2026 · Standardopen ↗
Assertion (A): Direction of force exerted on a current-carrying conductor placed in a magnetic field remains same if the directions of both magnetic field and current flowing through the conductor are reversed.
Reason (R) : The direction of force exerted on a current-carrying conductor placed in an external magnetic field can be determined by using magnetic compass.
  • (a)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
  • (b)Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
  • (c)Assertion (A) is true, but Reason (R) is false.
  • (d)Assertion (A) is false, but Reason (R) is true.
Show SolutionHide Solution↓
(C) / Assertion (A) is true, but reason (R) is false. (1 Mark)

Domestic electric circuits

2 Marks Questions
62 Marks · March 2026 · Standardopen ↗
A fuse in electric circuit is rated $4\text{ A}$. Can it be used with an electric heater of rating $2\text{ kW}$, $200\text{ V}$ ? Explain your answer.
Show SolutionHide Solution↓
• $I = \frac{P}{V}$
$I = \frac{2000}{200}$
$I = 10\text{ A}$ (½ Mark)
• Current passing through electric heater is 10A which is much more than rated value (4A) of fuse. Hence fuse will melt and break the circuit. So, it cannot be used. (1 Mark)
3 Marks Questions
73 Marks · March 2026 · Standardopen ↗
State the role of fuse and earthing in domestic electric circuit. Suggest any two precautions to be taken to avoid electrical accidents.
Show SolutionHide Solution↓
• Fuse is a safety device which melts and breaks the electric circuit when unduly high electric current flows due to overloading and prevents damages to appliances and circuit. (1 Mark)
• Earth wire provides a low resistance conducting path for current and ensures leakage of current from metallic body of appliances towards the earth and prevents severe electric shock. (1 Mark)
Two precautions
(i) Use of fuse of appropriate rating. (½ Mark)
(ii) Avoid overloading. (½ Mark)
(iii) Metallic appliances should be earthed. (½ Mark)
(Any two, Any other precautions)
5 Marks Questions
85 Marks · March 2026 · Standardopen ↗
Attempt either (a) or (b) :
(a) A person was repairing an electric heater. He observed that there were three different connecting wires of three different colours in the cable attached to the heater.
(i) What are these three different wires called ? Name them colourwise.
(ii) What is the value of standard potential difference at which electricity is supplied in Indian homes for lighting?
(iii) What is the role of (I) earthing and (II) fuse in domestic electric circuits ?
Show SolutionHide Solution↓
(a) (i) Live wire - Red
(
frac{1}{2})
Neutral wire - Black
(
frac{1}{2})
Earth wire - Green
(
frac{1}{2})
(ii) 220V
(1)
(iii) (I) Earth wire provides a low resistance conducting path for current and thus, protect us from electric shock due to leakage of electric current to metallic body of electrical appliances.
(1)
(II) Fuse is a safety device which melts and breaks the electric circuit when unduly high electric current flows due to overloading and prevents damage to appliances and circuit.
(1)
95 Marks · March 2026 · Standardopen ↗
(i) List any two features of the electric current used in the houses of India.
(ii) Write any two differences between direct current and an alternating current.
(iii) How will you identify live wire and neutral wire in a domestic electric circuit ?
Show SolutionHide Solution↓
(i) Features:
• Direction of current changes periodically/ alternating current. (1 Mark)
• Frequency of current supplied in our houses is 50 Hz. (1 Mark)
(ii)
Direct current: (I) Flows in one direction, (II) Sources: Cell / battery
Alternating current: (I) Reverses its direction periodically, (II) Source: Power plant (any other suitable difference) (1 + 1 Marks)
(iii) Live wire has red insulation cover and neutral wire has black insulation cover. (1 Mark)
105 Marks · March 2026 · Standardopen ↗
(i) Why is fuse an important component in our electric circuits ?
(ii) Distinguish between overloading and short-circuiting of a circuit.
(iii) Giving reason explain what type of materials are used in fuse wires.
Show SolutionHide Solution↓
(i) Because it is a safety device, which prevents the damage to electric appliances and circuit caused due to overloading. (1 Mark)
(ii)
Over loading: It is caused when too many appliances are connected to a single socket./ Due to accidental hike in the supply voltage.
Short circuiting: It is caused due to direct contact of live wire with the neutral wire. (2 Marks)
(iii) • A piece of wire made of a metal or an alloy. (1 Mark)
• appropriate (low) melting point. (1 Mark)