StudyOSStudyOS CBSE Study Material, Class 5–12

Magnetic Effects of Electric Current

NCERT Class 10 · Science Based on NCERT Class 10 Science textbook · Free CBSE study kit

Everything you need to ace this chapter, in one place.
Notes · Mind Map · Quiz · Assertion-Reason · Case Studies · Question Bank · Past Papers

Get Full Study Kit →
Studying with friends? Send them this chapter.

Chapter Notes

Overview
This chapter explores the relationship between electricity and magnetism, building on the heating effects of electric current studied in the previous chapter. The central idea is that an electric current produces a magnetic field, and this magnetic field can exert a force on a current-carrying conductor. Students must understand how to determine the direction of magnetic fields using rules like the Right-Hand Thumb Rule and the direction of force using Fleming’s Left-Hand Rule, and apply these concepts to devices like electromagnets and domestic electric circuits.
Key Concepts (13)
Magnetic field
The region surrounding a magnet, in which the force of the magnet can be detected.
e.g. When a compass is brought near a bar magnet, the needle deflects because it is in the magnetic field of the magnet.
Magnetic field lines
The lines along which iron filings align themselves around a magnet; they represent the magnetic field. By convention, they emerge from the north pole and merge at the south pole, and are closed curves.
e.g. Iron filings sprinkled around a bar magnet arrange in a pattern showing curved lines from north to south pole.
Compass needle
A small bar magnet whose north-seeking end points towards the geographic north pole and south-seeking end points towards the geographic south pole.
e.g. A compass placed near a current-carrying wire deflects, showing the presence of a magnetic field.
Right-hand thumb rule
A rule to find the direction of the magnetic field around a current-carrying straight conductor: if you hold the conductor in your right hand with the thumb pointing in the direction of current, your fingers will wrap around the conductor in the direction of the magnetic field lines.
e.g. For a current flowing from east to west in a horizontal wire, the magnetic field below the wire is clockwise when viewed from the east end.
Solenoid
A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder.
e.g. A current-carrying solenoid behaves like a bar magnet, with one end acting as north pole and the other as south pole.
Electromagnet
A magnet formed by placing a piece of magnetic material, like soft iron, inside a current-carrying solenoid.
e.g. A steel rod placed inside a solenoid becomes magnetised when current flows through the coil.
Fleming’s left-hand rule
A rule to find the direction of force on a current-carrying conductor placed in a magnetic field: stretch the thumb, forefinger, and middle finger of the left hand mutually perpendicular; if the forefinger points in the direction of the magnetic field and the middle finger in the direction of current, the thumb points in the direction of motion or force.
e.g. In Activity 12.7, when current flows from B to A and magnetic field is upward, the rod moves left, as given by this rule.
Live wire
The wire in domestic electric supply with red insulation, which carries current at a high potential (220 V relative to neutral).
e.g. In a household circuit, the live wire is connected to the switch before the appliance.
Neutral wire
The wire in domestic electric supply with black insulation, which is at zero potential relative to earth.
e.g. The neutral wire completes the circuit by providing a return path for current.
Earth wire
A safety wire with green insulation, connected to a metal plate deep in the earth, used to provide a low-resistance path for leakage current to prevent electric shock.
e.g. The metallic body of a refrigerator is connected to the earth wire so that if a fault occurs, current flows to earth instead of through a user.
Electric fuse
A safety device that melts and breaks the circuit when unduly high current flows, preventing damage due to short-circuiting or overloading.
e.g. A 5 A fuse in a lighting circuit will melt if the current exceeds 5 A, protecting the bulbs and wiring.
Short-circuiting
A situation where the live wire and neutral wire come into direct contact, causing the current to increase abruptly.
e.g. If the insulation of wires is damaged, the live and neutral wires may touch, leading to a short circuit.
Overloading
A condition caused by connecting too many appliances to a single socket or an accidental hike in supply voltage, leading to excessive current.
e.g. Plugging multiple high-power appliances into one socket can cause overloading.
Formulas & Equations (1)
No explicit mathematical formula is given in this chapter.
Reads as: Not applicable
Variables: Not applicable
Use when: Not applicable
⚠ Not applicable
How It Works
Oersted’s experiment (Activity 12.1)
  1. Take a straight thick copper wire and place it between points X and Y in an electric circuit, perpendicular to the plane of paper.
  2. Place a small compass horizontally near the copper wire.
  3. Pass current through the circuit by inserting the key.
  4. Observe the deflection of the compass needle.
  5. The deflection shows that electric current produces a magnetic effect.
💡 The compass needle deflects only when current flows; reversing the current reverses the deflection direction.
Drawing magnetic field lines of a bar magnet (Activity 12.3)
  1. Place a bar magnet on a sheet of white paper fixed on a drawing board.
  2. Mark the boundary of the magnet.
  3. Place a compass near the north pole of the magnet.
  4. Mark the positions of the two ends of the compass needle.
  5. Move the compass to a new position such that its south pole occupies the previous north pole position.
  6. Repeat step by step until you reach the south pole of the magnet.
  7. Join the marked points with a smooth curve to represent a field line.
  8. Repeat to draw as many lines as possible.
💡 The direction of the magnetic field at a point is the direction in which the north pole of the compass needle moves.
Magnetic field due to a current through a straight conductor (Activity 12.4 and 12.5)
  1. Connect a long straight copper wire in series with cells and a plug key.
  2. Place the wire parallel to and over a compass needle.
  3. Plug the key and observe the deflection of the north pole.
  4. If current flows from north to south, the north pole moves towards east.
  5. Reverse the cell connections to reverse current direction; the needle now moves towards west.
  6. To see field pattern, insert the wire through a cardboard, sprinkle iron filings, and tap the cardboard.
  7. Iron filings align in concentric circles around the wire.
  8. Place a compass at a point to find the direction of the field lines.
💡 The magnetic field lines are concentric circles centred on the wire; the direction is given by the right-hand thumb rule.
Magnetic field due to a current through a circular loop
  1. Bend a straight wire into a circular loop and pass current through it.
  2. At every point on the wire, the magnetic field lines are concentric circles that become larger as distance increases.
  3. At the centre of the loop, the arcs of these circles appear as straight lines.
  4. Every section of the wire contributes to the magnetic field in the same direction within the loop.
  5. For a coil with n turns, the field produced is n times that of a single turn.
💡 The magnetic field at the centre of a circular loop is uniform and perpendicular to the plane of the loop.
Magnetic field due to a current in a solenoid
  1. Wrap insulated copper wire closely in the shape of a cylinder to form a solenoid.
  2. Pass current through the solenoid.
  3. The field lines inside the solenoid are parallel straight lines, indicating a uniform magnetic field.
  4. One end of the solenoid behaves as a north pole and the other as a south pole, similar to a bar magnet.
  5. A strong magnetic field inside can magnetise a soft iron core placed inside, forming an electromagnet.
💡 The magnetic field inside a long straight solenoid is the same at all points (uniform).
Force on a current-carrying conductor in a magnetic field (Activity 12.7)
  1. Suspend a small aluminium rod AB horizontally from a stand using connecting wires.
  2. Place a strong horseshoe magnet such that the rod lies between the poles with magnetic field directed upwards (north pole below, south pole above).
  3. Connect the rod in series with a battery, key, and rheostat.
  4. Pass current from end B to end A; observe the rod displaced towards the left.
  5. Reverse the direction of current; the rod now moves towards the right.
  6. Reverse the direction of the magnetic field (interchange poles); the direction of force reverses again.
  7. The force is largest when current and magnetic field are perpendicular to each other.
💡 The direction of force is given by Fleming’s left-hand rule; it is perpendicular to both current and magnetic field.
Domestic electric circuit operation
  1. Electric power enters the house through a main supply (overhead or underground) with live (red), neutral (black), and earth (green) wires.
  2. The potential difference between live and neutral is 220 V.
  3. Wires pass through an electricity meter and a main fuse to the main switch.
  4. Two separate circuits are used: one of 15 A rating for high-power appliances (geysers, air coolers) and one of 5 A rating for bulbs, fans, etc.
  5. Appliances are connected in parallel across live and neutral wires to ensure equal potential difference.
  6. Each appliance has a separate switch to control current flow.
  7. The earth wire is connected to the metallic body of appliances as a safety measure.
💡 The earth wire provides a low-resistance path for leakage current, preventing electric shock.
Exam Traps — Don't Make These Mistakes
⚠ Direction of magnetic field inside a magnet
✗ Magnetic field lines go from north to south pole inside the magnet.
→ Inside the magnet, the direction of field lines is from south pole to north pole, not north to south. Outside, it is from north to south.
✓ Magnetic field lines are closed curves; outside the magnet they go from north to south, and inside the magnet they go from south to north.
⚠ Fleming’s left-hand rule for electron
✗ For an electron moving in a magnetic field, the direction of current is taken in the direction of motion of the electron.
→ The direction of current is taken opposite to the direction of motion of electrons (since electrons are negatively charged).
✓ For an electron, the direction of current is opposite to its direction of motion. Apply Fleming’s left-hand rule using this current direction.
⚠ Magnetic field at the centre of a circular loop
✗ The magnetic field at the centre of a circular loop is zero.
→ The magnetic field at the centre is not zero; it is the sum of contributions from all sections of the wire, all in the same direction.
✓ The magnetic field at the centre of a current-carrying circular loop is perpendicular to the plane of the loop and has a non-zero value.
⚠ Function of earth wire
✗ The earth wire prevents overloading.
→ The earth wire is a safety measure to prevent electric shock by providing a low-resistance path for leakage current; it does not prevent overloading.
✓ The earth wire ensures that any leakage of current to the metallic body of an appliance keeps its potential at earth potential, preventing severe electric shock to the user.
⚠ Short-circuit vs overloading
✗ Short-circuit and overloading are the same thing.
→ Short-circuit occurs when live and neutral wires come into direct contact, causing a sudden increase in current. Overloading can be due to connecting too many appliances or a hike in supply voltage.
✓ Short-circuit is a direct contact between live and neutral wires; overloading is excessive current due to too many appliances or high voltage. Both can cause damage, but they are different phenomena.
Compare & Contrast
Shape of field lines
Magnetic field due to a straight conductor
Magnetic field due to a circular loop
For a straight conductor, field lines are concentric circles centred on the wire. For a circular loop, field lines are concentric circles around the wire that become straight lines at the centre of the loop.
Purpose
Right-hand thumb rule
Fleming’s left-hand rule
Right-hand thumb rule is used to find the direction of the magnetic field around a current-carrying conductor. Fleming’s left-hand rule is used to find the direction of force on a current-carrying conductor placed in a magnetic field.
Exam Focus
Marks pattern: 2 MCQs (1 mark each), 1 Short Answer (3 marks), 1 Long Answer (5 marks) — total 10 marks typically.
Most asked: Right-hand thumb rule and its application · Fleming’s left-hand rule and force on a current-carrying conductor · Magnetic field lines of a bar magnet and their properties · Magnetic field due to a solenoid and electromagnet · Domestic electric circuits: live, neutral, earth wire, and fuse
Don't skip: Numerical or descriptive question on Fleming’s left-hand rule (often 3 marks); Diagram-based question on magnetic field lines around a straight conductor or solenoid (5 marks)
One-Line Revision (read aloud before the exam)
  1. A compass needle is a small bar magnet; its north pole points towards geographic north.
  2. Magnetic field lines emerge from the north pole and merge at the south pole outside the magnet, and are closed curves.
  3. No two magnetic field lines intersect each other because that would imply two directions of the magnetic field at the point of intersection.
  4. The right-hand thumb rule gives the direction of magnetic field around a current-carrying straight conductor.
  5. The magnetic field produced by a current-carrying circular loop at its centre is perpendicular to the plane of the loop.
  6. A solenoid carrying current behaves like a bar magnet with a uniform magnetic field inside.
  7. An electromagnet is made by placing a soft iron core inside a current-carrying solenoid.
  8. Fleming’s left-hand rule gives the direction of force on a current-carrying conductor in a magnetic field.
  9. The force on a current-carrying conductor is largest when the current and magnetic field are perpendicular to each other.
  10. In domestic circuits, the live wire (red) and neutral wire (black) have a potential difference of 220 V.
  11. The earth wire (green) is a safety measure that prevents electric shock by providing a low-resistance path for leakage current.
  12. An electric fuse melts and breaks the circuit during short-circuit or overloading to prevent damage.
  13. Short-circuit occurs when live and neutral wires come into direct contact, causing a sudden increase in current.
  14. Overloading can be caused by connecting too many appliances to a single socket or by a hike in supply voltage.

MCQs — 10 Questions with Answers

Q1. In Activity 12.1, a student passes current through a straight copper wire placed perpendicular to the plane of paper. A compass needle placed horizontally near the wire deflects. Which of the following best explains why the needle deflects?

  • A. The electric current through the wire produces a magnetic field around it, which exerts a force on the compass needle's magnetic poles. ✓
  • B. The copper wire attracts the iron present in the compass needle due to its electrical properties.
  • C. The current heats the wire, and the heat causes the compass needle to move.
  • D. The magnetic field of Earth changes when current flows through the wire.

Answer: A — Electric current through a conductor creates a magnetic field (Oersted's discovery) that exerts force on the compass needle; heat generation does not directly cause needle deflection, and the wire's electrical properties alone cannot attract a magnetic needle without a magnetic field.

Q2. A student sprinkles iron filings around a bar magnet and observes them arranging in a specific pattern. The student then sprinkles more iron filings very close to the poles of the magnet and observes they are much more densely packed. What does this observation demonstrate?

  • A. The magnetic field is stronger near the poles where field lines are crowded together. ✓
  • B. Iron filings are attracted to the poles because poles have greater mass.
  • C. The density of iron filings is higher near the poles due to gravity.
  • D. The poles have higher temperature which attracts iron filings magnetically.

Answer: A — According to the chapter, the relative strength of the magnetic field is shown by the closeness of field lines; where field lines are crowded (near poles), the field is stronger and exerts greater force on magnetic materials, not due to mass, gravity, or temperature.

Q3. Assertion (A): Magnetic field lines always emerge from the north pole of a magnet and merge into the south pole. Reason (R): The direction of the magnetic field is conventionally defined as the direction in which a north pole of a compass needle moves inside it. Choose the correct option:

  • A. Both A and R are true and R is the correct explanation of A ✓
  • B. Both A and R are true but R is not the correct explanation of A
  • C. A is true but R is false
  • D. A is false but R is true

Answer: A — Both statements are true and directly connected: field lines emerge from north poles and merge into south poles precisely because the field direction is defined by the direction a north pole would move, which is away from north poles and toward south poles.

Q4. A physics teacher sets up an experiment where a compass is placed at different points around a straight current-carrying wire. At one position, the compass needle points North-South. At another position slightly to the side, the needle rotates 90 degrees. What can the student infer about the magnetic field produced by the wire?

  • A. The magnetic field direction changes at different points around the wire, forming concentric circles around it. ✓
  • B. The Earth's magnetic field is interfering with the wire's magnetic field at different positions.
  • C. The wire's magnetic field strength is different at different distances, causing the needle to rotate.
  • D. The compass needle is defective and gives inconsistent readings.

Answer: A — A current-carrying wire produces a circular magnetic field around it where the direction changes at each point (tangent to circles), causing the compass needle to point in different directions at different positions; field strength variation would not cause rotation of the needle but only affect deflection magnitude.

Q5. A student carefully marks the path of a compass needle as it is moved step-by-step around a bar magnet, with each new position overlapping the previous one, starting from the north pole and ending at the south pole. The student then joins all marked points with a smooth curve. What does this curve represent?

  • A. A magnetic field line showing the path along which the magnetic force acts. ✓
  • B. The equator of the bar magnet.
  • C. The boundary between the magnet's north and south poles.
  • D. A circular orbit that compass needles naturally follow around magnets.

Answer: A — This procedure (Activity 12.3) explicitly demonstrates drawing magnetic field lines by following the needle's orientation at successive points; the curve represents a field line along which the magnetic field direction is tangent, not a physical boundary or orbit.

Q6. Assertion (A): Two magnetic field lines never cross each other at any point. Reason (R): If two field lines crossed, the compass needle at that point would have to point in two different directions simultaneously, which is physically impossible. Choose the correct option:

  • A. Both A and R are true and R is the correct explanation of A ✓
  • B. Both A and R are true but R is not the correct explanation of A
  • C. A is true but R is false
  • D. A is false but R is true

Answer: A — Both statements are true and causally linked: field lines cannot cross because at any intersection point a compass needle would experience conflicting magnetic field directions, violating the fundamental property that a magnetic field has a unique direction at every point in space.

Q7. In a school laboratory, a student observes that when current flows through a wire, the compass needle beside it deflects, but when the current is switched off, the needle returns to its original position. What does this observation indicate about the relationship between electric current and magnetic field?

  • A. The magnetic field is produced by the electric current and exists only when current flows. ✓
  • B. The compass needle has lost its magnetism after being used once.
  • C. The Earth's magnetic field is restored when the current stops.
  • D. The wire becomes permanently magnetized only when current flows through it.

Answer: A — The reversible deflection directly demonstrates that the magnetic field is a direct consequence of current flow; when current ceases, the induced magnetic field disappears, causing the needle to return to Earth's field direction, not indicating needle demagnetization or permanent wire magnetization.

Q8. Assertion (A): Inside a bar magnet, magnetic field lines run from the south pole to the north pole. Reason (R): The magnetic field inside the magnet is opposite in direction to the field outside the magnet. Choose the correct option:

  • A. Both A and R are true and R is the correct explanation of A
  • B. Both A and R are true but R is not the correct explanation of A ✓
  • C. A is true but R is false
  • D. A is false but R is true

Answer: B — A is true (field lines run from S to N inside) and R is true (inside and outside directions are opposite), but R does not explain A; rather, both facts together show that field lines form closed curves, which is the actual reason for the reversal inside the magnet.

Q9. A student observes the pattern of iron filings around a bar magnet and notes that the filings are sparse in the middle region between the two poles and extremely dense right at the poles. What is the best explanation for this observation?

  • A. The magnetic field is weak in the middle region and very strong at the poles, as indicated by the spacing of field lines. ✓
  • B. Iron filings are repelled from the middle region by the Earth's magnetic field.
  • C. The poles have higher temperature which attracts more iron filings.
  • D. The middle region has less iron content in the filings.

Answer: A — Field line density directly correlates with field strength per the chapter; crowded field lines at poles indicate stronger fields (greater force), while sparse distribution in the middle region indicates weaker fields, not temperature effects or Earth's field repulsion.

Q10. Assertion (A): A magnetic field is considered to be a vector quantity. Reason (R): Magnetic field has both magnitude (strength) and direction (indicated by the path of field lines). Choose the correct option:

  • A. Both A and R are true and R is the correct explanation of A ✓
  • B. Both A and R are true but R is not the correct explanation of A
  • C. A is true but R is false
  • D. A is false but R is true

Answer: A — The chapter explicitly states that magnetic field has both direction and magnitude, which is the defining characteristic of vector quantities; the reason directly explains why it is a vector.

Flashcards

What did Hans Christian Oersted discover in 1820?

He discovered that electric current through a metallic wire produces a magnetic field, proving electricity and magnetism are related phenomena.

Define magnetic field.

The region surrounding a magnet in which the magnetic force can be detected is called a magnetic field.

What are magnetic field lines?

Imaginary lines that show the path along which a north pole of a compass needle would move inside a magnetic field.

Why do iron filings arrange in a specific pattern around a magnet?

Iron filings align themselves along magnetic field lines because the magnet exerts a magnetic force on them.

What is the direction convention for magnetic field lines?

Field lines emerge from the north pole and merge into the south pole; inside the magnet they flow from south pole to north pole.

What does the closeness of magnetic field lines indicate?

The closer (or denser) the field lines, the stronger the magnetic field at that region.

Can two magnetic field lines cross each other?

No, two field lines never cross because it would mean the compass needle points in two directions simultaneously, which is impossible.

Why does a compass needle deflect when near a current-carrying wire?

The electric current through the wire produces a magnetic field that exerts a force on the compass needle's magnetic poles.

What determines the strength of a magnetic field around a straight conductor?

The strength of the magnetic field depends on the magnitude of the electric current flowing through the conductor.

Are magnetic field lines open or closed curves?

Magnetic field lines are closed curves because they emerge from the north pole and eventually merge into the south pole, forming complete loops.

Important Board Questions

Explain with an activity how you would show that electric current produces a magnetic field. [2 marks]

Activity 12.1: Use a straight copper wire carrying current placed over a compass needle; observe compass needle deflection when key is plugged in. The deflection proves current creates magnetic field.

What are magnetic field lines? Describe three important properties of magnetic field lines with reasons. [3 marks]

Field lines are imaginary paths showing direction of magnetic field. Three properties: (1) emerge from north pole and merge at south pole—by convention; (2) never cross—compass cannot point two directions; (3) density shows strength—crowded lines mean stronger field.

Describe with a labeled diagram how you would draw magnetic field lines around a bar magnet using a compass. What does the pattern of field lines tell you about the magnetic field? [5 marks]

Use Activity 12.3 procedure: place compass near magnet, mark needle positions, move compass so south pole occupies previous north pole position, repeat until south pole reached, join points to draw field line. Repeat for multiple lines. Pattern shows: field emerges from north pole, closes through south pole, crowded lines indicate stronger regions, field strength increases near poles, line density represents field magnitude.

Assertion-Reason Questions for Magnetic Effects of Electric Current

Q1. Assertion (A):

Iron filings arrange in a specific pattern around a bar magnet without any external force applied to individual filings.

Reason (R):

The iron filings experience a magnetic force from the magnetic field produced by the bar magnet.

Answer: A — Both A and R are true, and R is the correct explanation of A — Both statements are true, and the reason correctly explains why iron filings arrange in patterns—they experience forces from the magnetic field. This directly supports the assertion about pattern formation.

Q2. Assertion (A):

Magnetic field lines never cross each other at any point.

Reason (R):

Magnetic field lines represent the path traveled by electrons in an atom.

Answer: C — A is true but R is false — The assertion is true—field lines never cross because a field would have two directions at intersection, which is impossible. However, the reason is false; field lines represent the direction of the magnetic field, not electron paths.

Q3. Assertion (A):

The direction of the compass needle's deflection changes when the direction of electric current through a conductor is reversed.

Reason (R):

Reversing the current direction reverses the direction of the magnetic field produced around the conductor.

Answer: A — Both A and R are true, and R is the correct explanation of A — Both statements are true and the reason correctly explains the assertion. Activity 12.4 demonstrates this relationship between current direction and magnetic field direction.

Unlock more Assertion-Reason questions in Premium — unlock →

Case-Based Questions (CBQ) for Magnetic Effects of Electric Current

Case Study:

A science class conducted an experiment to study magnetic fields produced by current-carrying conductors. They set up a straight copper wire connected to a 3V battery with a variable rheostat. A compass was placed at a fixed distance (5 cm) from the wire. When 0.5 A current flowed through the wire, the compass needle deflected by 15°. When the current was increased to 1.0 A, the deflection increased to 28°. When the current was reversed to 0.5 A (opposite direction), the needle deflected by 15° in the opposite direction. This experiment was repeated at 10 cm distance, where deflections were smaller for the same currents.

Q1. What does the increase in deflection from 15° to 28° when current increases from 0.5 A to 1.0 A indicate?

  • A. The magnetic field strength increases with current ✓
  • B. The copper wire becomes hotter
  • C. The compass needle becomes weaker
  • D. The battery voltage is insufficient

Answer: A

Q2. Why did the deflection occur in the opposite direction when current direction was reversed?

  • A. The compass needle reversed its polarity
  • B. The magnetic field direction depends on current direction ✓
  • C. The distance from the wire changed
  • D. The Earth's magnetic field reversed

Answer: B

Q3. What observation at 10 cm distance (smaller deflections) demonstrates according to the chapter's principles?

  • A. The current decreased at greater distances
  • B. The magnetic field strength decreases with distance from the conductor ✓
  • C. The compass becomes less sensitive at greater distances
  • D. The wire loses its magnetic properties farther away

Answer: B

Q4. If field lines were drawn around this current-carrying wire based on this experiment, how would their spacing vary?

  • A. Equally spaced throughout
  • B. Field lines cannot be drawn for straight wires
  • C. Farther apart near the wire, closer at greater distances
  • D. Closer together near the wire, farther apart at greater distances ✓

Answer: D

Unlock more case studies in Premium — unlock →

Previous Year Questions (PYQ) for Magnetic Effects of Electric Current

Real CBSE board exam questions from past papers — free to attempt.

CBSE 2026 · Set 31/4/1 · 1 mark

Assertion (A): With the help of compass, magnetic field lines can be traced outside the bar magnet. Reason (R): The north pole of a compass needle always points towards the south pole of the magnet when brought close to it.

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

CBSE 2026 · Set 31/4/1 · 2 marks

(B) How is an electromagnet made? Write any two ways by which the strength of electromagnet can be increased.

CBSE 2026 · Set 31/4/1 · 3 marks

[Diagram-based question — skipped]

CBSE 2026 · Set 31/4/2 · 3 marks

[Diagram-based question — skipped] On the basis of the given circuit arrangement, answer the following questions: (a) What happens to the rod AB when the key K is closed and why? (b) Name and state the rule that determines this behaviour of the rod AB in the above situation.

CBSE 2026 · Set 31/4/2 · 2 marks

(B) How is an electromagnet made ? Write any two ways by which the strength of electromagnet can be increased.

CBSE 2026 · Set 31/4/3 · 2 marks

How is an electromagnet made? Write any two ways by which the strength of electromagnet can be increased.

CBSE 2026 · Set 31/4/3 · 3 marks

[Diagram-based question — skipped] (a) What happens to the rod AB when the key K is closed and why? (b) Name and state the rule that determines this behaviour of the rod AB in the above situation.

CBSE 2026 · Set 31/5/1 · 1 mark

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.

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

CBSE 2026 · Set 31/5/1 · 5 marks

(A) (i) Draw a diagram showing the magnetic field lines around a bar magnet. Write any two characteristics of magnetic field lines. (ii) Write the statement of Right hand thumb rule. (iii) The concentric circles representing the magnetic field around a current carrying straight wire become larger and larger as we move away from the wire. How does magnetic field change on these concentric circles?

CBSE 2026 · Set 31/5/2 · 1 mark

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.

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

CBSE 2026 · Set 31/5/3 · 5 marks

(A) (i) State the rule which gives the direction of force acting on a current carrying conductor placed in a uniform magnetic field. (ii) Name any two devices which work on the basis of an interaction between magnetic field and current carrying conductor. (iii) Observe the given diagrams: Comment on the magnitude of force on electron in both the cases and give reason for your answer.

CBSE 2026 · Set 31/2/1 · 1 mark

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.

  • 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.

See all 69 board PYQs for this chapter — open PYQ tab →

Class 10 Science Formula Sheet

Every formula and chemical equation from the 10 chapters on one page, checked against the NCERT textbook and the CBSE 2026-27 syllabus. Free PDF download.

View the formula sheet →

Class 10 Science Previous Year Questions, Chapter-wise

All 875 CBSE board questions from 2022–2026, sorted by chapter and question type. Free PDF download.

See all past board questions →

Next chapterOur Environment →
Found this useful? Share it with your class group.

You've seen the free preview. Open the full interactive study kit — mind map, instant-graded quiz, progress tracking — free, no sign-in required.

Open Full Study Kit — Free →

Premium unlocks the full Question Bank, Daily Practice Papers, Chapter Quiz and Full Mock Papers for every chapter.