---
title: "Magnetic Effects of Electric Current: CBSE Class 10 Science previous year questions"
url: https://www.swavid.com/cbse/class-10/science/pyq/magnetic-effects-of-electric-current
---

# Magnetic Effects of Electric Current: CBSE Class 10 Science previous year questions

14 questions from CBSE Class 10 board papers, newest first, each with full working.

## CBSE Class 10 Science Question Paper 2026 (Set 31/1/1) with Solutions

### Question 36

*3 marks · Short answer*

(a) Describe an activity to show that a current carrying conductor, placed in an external magnetic field experiences a force.
(b) Imagine that you are sitting in a chamber with your back to one wall. An electron beam, moving horizontally towards the front wall from the back wall, is deflected by a strong magnetic field to your right side. Find the direction of the magnetic field.

**Solution**

1. Activity: Suspend an aluminum rod horizontally between the poles of a strong horseshoe magnet and connect it to a battery and switch.
2. Observation: When current flows through the rod, it experiences a force and gets displaced.
3. Direction: Using Fleming's Left-Hand Rule, since the current is towards the back wall and force is to the right, the magnetic field is vertically downwards.

**Answer:** The magnetic field is directed vertically downwards.

> Common mistake: Forgetting that the direction of conventional current is opposite to the direction of electron flow.

### Question 37

*3 marks · Short answer*

(a) The pattern of magnetic field due to a current carrying wire depends upon the shape made by that wire. Justify.
(b) A current carrying straight wire AB is shown in the given diagram. Out of X, Y and Z on which point will the strength of magnetic field be maximum and why ?

**Solution**

1. The magnetic field pattern depends on the shape: a straight wire produces concentric circles, a loop produces circles near the wire, and a solenoid produces a pattern similar to a bar magnet.
2. The strength of the magnetic field is inversely proportional to the distance from the wire.
3. Point X is closest to the wire, so the magnetic field strength is maximum at X.

**Answer:** The strength is maximum at point X because it is closest to the wire.

> Common mistake: Stating that the field is uniform everywhere near the wire.

## CBSE Class 10 Science Question Paper 2025 (Set 31/1/1) with Solutions

### Question 19

*1 mark · Assertion and reason*

Assertion (A) : No two magnetic field lines are found to cross each other.
Reason (R) : The compass needle cannot point towards two directions at the point of intersection of two magnetic field lines.

- Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
- Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
- Assertion (A) is true, but Reason (R) is false.
- Assertion (A) is false, but Reason (R) is true.

**Solution**

1. Magnetic field lines never intersect because if they did, the compass needle would point in two directions at the same time, which is not possible.

**Answer:** Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).

> Common mistake: Confusing the direction of magnetic field lines with electric field lines.

## CBSE Class 10 Science Question Paper 2024 (Set 31/1/1) with Solutions

### Question 14

*1 mark · MCQ*

The pattern of the magnetic field produced inside a current carrying solenoid is :

- (a)
- (b)
- (c)
- (d)

**Solution**

1. The magnetic field inside a current-carrying solenoid is uniform, represented by parallel straight field lines.

**Answer:** (b)

> Common mistake: Confusing the uniform parallel field lines inside the solenoid with the concentric circles around a straight current-carrying conductor.

### Question 26

*2 marks · Very short answer*

(i) Two magnetic field lines do not intersect each other. Why ?
(ii) How is a uniform magnetic field in a given region represented ? Draw a diagram in support of your answer.

**Part (i)**

1. Two magnetic field lines never intersect each other because if they did, it would mean that at the point of intersection, the compass needle points in two different directions, which is not possible.

Answer (i): Intersection would imply two directions for the magnetic field at a single point.

**Part (ii)**

1. A uniform magnetic field is represented by parallel and equidistant field lines.
2. Diagram: Draw a set of straight, parallel, equally spaced horizontal lines with arrows pointing in the same direction.

Answer (ii): Represented by parallel, equidistant field lines.

**Answer:** Magnetic field lines never intersect and uniform fields are shown by parallel equidistant lines.

> Common mistake: Writing that the magnetic field has two north poles instead of two directions at the point of intersection.

### Question 32

*3 marks · Short answer*

Name and state the rule to determine the direction of a :
(i) magnetic field produced around a current carrying straight conductor.
(ii) force experienced by a current carrying straight conductor placed in a magnetic field which is perpendicular to it.

**Part (i)**

1. Rule name: Right-hand thumb rule.
2. Statement: If you hold a current-carrying straight conductor in your right hand such that the thumb points in the direction of current, then your fingers wrap around the conductor in the direction of the field lines of the magnetic field.

Answer (i): Right-hand thumb rule: Thumb points along current, wrapped fingers show magnetic field direction.

**Part (ii)**

1. Rule name: Fleming's left-hand rule.
2. Statement: Stretch the thumb, forefinger, and middle finger of your left hand such that they are mutually perpendicular. If the forefinger points in the direction of magnetic field and the middle finger in the direction of current, then the thumb will point in the direction of motion or force acting on the conductor.

Answer (ii): Fleming's left-hand rule: Forefinger = magnetic field, middle finger = current, thumb = force.

**Answer:** Right-hand thumb rule determines the magnetic field around a straight conductor, and Fleming's left-hand rule determines the force on a current-carrying conductor.

> Common mistake: Mixing up Fleming's left-hand rule (used for force on current-carrying conductor) with Fleming's right-hand rule (used for electromagnetic induction).

## CBSE Class 10 Science Question Paper 2023 (Set 31/1/1) with Solutions

### Question 16

*1 mark · MCQ*

The resultant magnetic field at point 'P' situated midway between two parallel wires (placed horizontally) each carrying a steady current $I$ is

[Diagram showing parallel wires AB and CD with point P in between]

- in the same direction as the current in the wires.
- in the vertically upward direction.
- zero
- in the vertically downward direction.

**Solution**

1. According to the right-hand thumb rule, the magnetic field produced by each parallel wire carrying current in the same direction points in opposite directions at the midway point P.
2. Since the magnitudes of the magnetic fields are equal and their directions are opposite, they cancel each other out, making the resultant magnetic field zero.

**Answer:** "(c) zero"

> Common mistake: Assuming the magnetic fields add up instead of opposing each other at the midpoint.

### Question 20

*1 mark · Assertion and reason*

Assertion (A) : The strength of the magnetic field produced at the centre of a current carrying circular coil increases on increasing the number of turns in it.
Reason (R) : The current in each circular turn has the same direction and the magnetic field due to each turn then just adds up.

- Both (A) and (R) are true and (R) is the correct explanation of (A).
- Both (A) and (R) are true, but (R) is not the correct explanation of (A).
- (A) is true, but (R) is false.
- (A) is false, but (R) is true.

**Solution**

1. The strength of the magnetic field produced by a circular coil is directly proportional to the number of turns in it, so increasing the turns increases the magnetic field strength.
2. Since the current in each circular turn flows in the same direction, the magnetic field produced by each individual turn adds up.

**Answer:** Both (A) and (R) are true and (R) is the correct explanation of (A).

> Common mistake: Failing to recognize that magnetic fields of individual turns in the same direction reinforce each other.

### Question 32

*3 marks · Short answer*

(a) (i) State the rule used to find the force acting on a current carrying conductor placed in a magnetic field.
(ii) Given below are three diagrams showing entry of an electron in a magnetic field. Identify the case in which the force will be (1) maximum and (2) minimum respectively. Give reason for your answer.

[Diagrams (i), (ii), (iii) showing electron entering magnetic field]

**Part (a) (i)**

1. Stretch the thumb, forefinger and middle finger of your left hand such that they are mutually perpendicular.
2. If the first finger points in the direction of magnetic field and the second finger in the direction of current, then the thumb will point in the direction of motion or the force acting on the conductor.

Answer (a) (i): Fleming's Left-Hand Rule is used to find the direction of force.

**Part (a) (ii)**

1. The magnetic force on a moving charge is given by $F = Bqv \sin\theta$, where $\theta$ is the angle between the velocity of the charge and the magnetic field.
2. The force is maximum when $\theta = 90^\circ$ (perpendicular entry) and minimum when $\theta = 0^\circ$ or $180^\circ$ (parallel or anti-parallel entry).

Answer (a) (ii): Maximum force occurs when the electron enters perpendicular to the magnetic field, and minimum (zero) force occurs when it enters parallel to the magnetic field.

**Answer:** Fleming's Left-Hand Rule is used; force is maximum when the direction of motion is perpendicular to the magnetic field and minimum when parallel.

> Common mistake: Confusing Fleming's Left-Hand Rule (used for motor/force) with Fleming's Right-Hand Rule (used for generator/induced current).

### Question 32 (OR)

*3 marks · Short answer*

(b) (i) Draw the pattern of magnetic field lines of (1) a current carrying solenoid (2) a bar magnet
(ii) List two distinguishing features between the two fields.

**Part (b) (i)**

1. Draw a solenoid with closed loops of magnetic field lines passing through it, emerging from the North pole and entering the South pole outside.
2. Draw a bar magnet showing closed continuous magnetic field lines directed from North pole to South pole outside the magnet and South to North inside.

Answer (b) (i): The field line patterns resemble each other, with the solenoid having uniform parallel lines inside.

**Part (b) (ii)**

1. The magnetic field inside a solenoid is uniform and parallel, whereas inside a bar magnet it is non-uniform.
2. The strength of the magnetic field can be changed in a current-carrying solenoid by altering the current or number of turns, but for a permanent bar magnet, it is fixed.

Answer (b) (ii): 1. Field inside a solenoid is uniform while inside a bar magnet it varies. 2. Solenoid field strength is adjustable, bar magnet field strength is constant.

**Answer:** Magnetic field lines of a solenoid are similar to those of a bar magnet; key difference is that field lines inside a solenoid are parallel uniform straight lines.

> Common mistake: Drawing field lines intersecting each other or omitting arrowheads indicating the direction of field lines.

## CBSE Class 10 Science Question Paper 2022 (Set 31/1/1) with Solutions

### Question 6

*2 marks · Short answer*

(a) (i) Name and state the rule to determine the direction of force experienced by a current carrying straight conductor placed in a uniform magnetic field which is perpendicular to it.
(ii) An alpha particle while passing through a magnetic field gets projected towards north. In which direction will an electron project when it passes through the same magnetic field ?

**Part (i)**

1. Name: Fleming's Left-Hand Rule.
2. Statement: Stretch the thumb, forefinger and middle finger of your left hand such that they are mutually perpendicular. If the first finger points in the direction of magnetic field and the second finger in the direction of current, then the thumb will point in the direction of motion or the force acting on the conductor.

Answer (i): Fleming's Left-Hand Rule states that the thumb, forefinger and middle finger of the left hand point in the direction of force, magnetic field, and current respectively when mutually perpendicular.

**Part (ii)**

1. An alpha particle is a positively charged particle, so its motion towards north constitutes a conventional current towards north.
2. An electron is negatively charged, so its motion in the same magnetic field constitutes a current in the direction opposite to its motion.
3. Since the current due to an electron is opposite to that of an alpha particle, the force acting on the electron will be in the opposite direction to that acting on the alpha particle.
4. Therefore, the electron will project towards the south.

Answer (ii): Towards south

**Answer:** Fleming's Left-Hand Rule determines the force direction; the electron projects towards the south.

> Common mistake: Confusing the direction of conventional current for negatively charged particles like electrons.

### Question 6 (OR)

*2 marks · Short answer*

(b) (i) What is a solenoid ?
(ii) Draw the pattern of magnetic field lines of the magnetic field produced by a solenoid through which a steady current flows.

**Part (i)**

1. A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder is called a solenoid.

Answer (i): A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder.

**Part (ii)**

1. Diagram: Draw a cylindrical coil with current indicating arrows, showing magnetic field lines emerging from one end and entering the other, forming continuous closed loops inside and outside the solenoid, with parallel lines inside representing a uniform magnetic field.

Answer (ii): Field lines inside the solenoid are parallel straight lines indicating a uniform magnetic field, resembling a bar magnet.

**Answer:** A solenoid is a coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder.

> Common mistake: Drawing field lines that intersect or do not form continuous closed loops.

### Question 15

*4 marks · Case-based*

A student fixes a sheet of white paper on a drawing board using some adhesive materials. She places a bar magnet in the centre of it and sprinkles some iron filings uniformly around the bar magnet using a salt-sprinkler. On tapping the board gently, she observes that the iron filings have arranged themselves in a particular pattern.
(a) Draw a diagram to show this pattern of iron filings.
(b) Draw the magnetic field lines of a bar magnet showing the poles of the bar magnet as well as the direction of the magnetic field lines.
(c) (i) How is the direction of magnetic field at a point determined using the field lines ? Why do two magnetic field lines not cross each other ?

**Part (a)**

1. Iron filings align along the magnetic field lines when the drawing board is gently tapped.
2. The pattern shows concentration of iron filings near the poles of the bar magnet.

Answer (a): Iron filings arrange themselves in concentric curved patterns representing magnetic field lines around the bar magnet.

**Part (b)**

1. Draw closed loops emerging from the North pole and entering the South pole outside the magnet.
2. Inside the magnet, the field lines run from the South pole to the North pole with arrows marked accordingly.

Answer (b): Field lines directed from North to South outside the magnet and South to North inside.

**Part (c)(i)**

1. The direction of the magnetic field at any point is determined by drawing a tangent to the magnetic field line at that point.
2. Two magnetic field lines never cross each other because if they did, it would mean there are two directions of the magnetic field at the same point, which is physically impossible.

Answer (c)(i): Direction is given by the tangent to the field line; lines do not cross because a compass needle cannot point in two directions at once.

**Answer:** Magnetic field lines form continuous closed curves representing the direction and strength of the magnetic field.

> Common mistake: Stating that field lines intersect or failing to show arrows inside and outside the magnet.

### Question 15 (OR)

*4 marks · Case-based*

A student fixes a sheet of white paper on a drawing board using some adhesive materials. She places a bar magnet in the centre of it and sprinkles some iron filings uniformly around the bar magnet using a salt-sprinkler. On tapping the board gently, she observes that the iron filings have arranged themselves in a particular pattern.
(a) Draw a diagram to show this pattern of iron filings.
(b) Draw the magnetic field lines of a bar magnet showing the poles of the bar magnet as well as the direction of the magnetic field lines.
(ii) How are the magnetic field lines of a bar magnet drawn using a small compass needle ? Draw one magnetic field line each on both sides of the magnet.

**Part (a)**

1. Iron filings experience a force and arrange in definite curved patterns surrounding the bar magnet.
2. The pattern is densest near the poles.

Answer (a): Iron filings form curved patterns outlining the magnetic field.

**Part (b)**

1. Sketch closed continuous loops around the bar magnet indicating North and South poles.
2. Mark arrows pointing from North to South externally.

Answer (b): Bar magnet field lines diagram with proper pole markings and directional arrows.

**Part (ii)**

1. Place a small compass near the North pole of the bar magnet and mark the position of its north pointer.
2. Move the compass so that its south pole occupies the previous north position and repeat to trace a continuous line from North to South.

Answer (ii): Field lines are plotted step-by-step by shifting a compass needle along the deflection path from pole to pole.

**Answer:** Magnetic field lines can be mapped using a small compass needle placed near a bar magnet.

> Common mistake: Reversing the direction of magnetic field lines or missing the compass plotting technique steps.

## Related pages

- [Magnetic Effects of Electric Current: NCERT solutions](https://www.swavid.com/science/class/10/chapter/magnetic-effects-of-electric-current/ncert-solutions)
- [All CBSE Class 10 Science papers](https://www.swavid.com/cbse/class-10/science/previous-year-papers)

Solutions written by SwaVid, a personal AI tutor for Class 6 to 10 Maths and Science. Practise this chapter free: https://www.swavid.com/start/student