Q.1. When a small compass is placed near a current-carrying straight conductor, the compass needle
(i) remains unaffected
(ii) shows deflection
(iii) rotates continuously
(iv) points towards geographical north only
Answer: (ii) shows deflection

Q.2. The magnetic field lines around a bar magnet
(i) are straight parallel lines
(ii) start from south pole and end at north pole outside the magnet
(iii) emerge from north pole and merge at south pole outside the magnet
(iv) intersect each other
Answer: (iii) emerge from north pole and merge at south pole outside the magnet

Q.3. The magnetic field inside a long straight solenoid carrying current
(i) is zero
(ii) decreases from one end to the other
(iii) increases towards the ends
(iv) is uniform at all points
Answer: (iv) is uniform at all points

Q.4. Assertion (A): No two magnetic field lines intersect each other.
Reason (R): At the point of intersection, the compass needle would point in two directions, which is not possible.
(i) Both A and R are true and R is the correct explanation of A
(ii) Both A and R are true but R is not the correct explanation of A
(iii) A is true but R is false
(iv) A is false but R is true
Answer: (i) Both A and R are true and R is the correct explanation of A

Q.5. The direction of magnetic field around a straight current-carrying conductor can be determined by
(i) Fleming’s left-hand rule
(ii) Fleming’s right-hand rule
(iii) Right-hand thumb rule
(iv) Maxwell’s left-hand rule
Answer: (iii) Right-hand thumb rule

Q.6. If the direction of current in a straight conductor is reversed, the magnetic field produced
(i) increases
(ii) decreases
(iii) remains unchanged
(iv) is reversed
Answer: (iv) is reversed

Q.7. Match the following:

List I | List II
(a) Fleming’s left-hand rule | (1) Direction of induced current
(b) Fleming’s right-hand rule | (2) Electric motor
(c) Split ring | (3) Direction of force
(d) Electromagnetic induction | (4) Production of current due to changing magnetic field

(i) a-3, b-1, c-2, d-4
(ii) a-1, b-3, c-2, d-4
(iii) a-3, b-4, c-1, d-2
(iv) a-2, b-3, c-4, d-1
Answer: (i) a-3, b-1, c-2, d-4

Q.8. The force experienced by a current-carrying conductor placed in a magnetic field is maximum when the angle between current and magnetic field is
(i) 0°
(ii) 45°
(iii) 90°
(iv) 180°
Answer: (iii) 90°

Q.9. A device that converts electrical energy into mechanical energy is called
(i) electric generator
(ii) galvanometer
(iii) electric motor
(iv) transformer
Answer: (iii) electric motor

Q.10. When a magnet is moved towards a coil connected to a galvanometer, the galvanometer shows deflection because
(i) a magnetic field is produced in the magnet
(ii) a potential difference is induced in the coil
(iii) the coil becomes a permanent magnet
(iv) the galvanometer produces current
Answer: (ii) a potential difference is induced in the coil

Q.11. The magnetic field lines through the centre of a circular current-carrying coil are
(i) circular
(ii) semi-circular
(iii) straight and parallel
(iv) curved
Answer: (iii) straight and parallel

Q.12. If the current in a straight conductor is increased, the magnetic field at a given point around it
(i) decreases
(ii) increases
(iii) remains the same
(iv) becomes zero
Answer: (ii) increases

Q.13. Assertion (A): A solenoid behaves like a bar magnet when current passes through it.
Reason (R): One end of the solenoid acts as north pole and the other as south pole.
(i) Both A and R are true and R is the correct explanation of A
(ii) Both A and R are true but R is not the correct explanation of A
(iii) A is true but R is false
(iv) A is false but R is true
Answer: (i) Both A and R are true and R is the correct explanation of A

Q.14. The phenomenon by which a changing magnetic field in a conductor induces a current in another conductor is called
(i) magnetisation
(ii) electromagnetic induction
(iii) electric conduction
(iv) electrolysis
Answer: (ii) electromagnetic induction

Q.15. In a current-carrying solenoid, the strength of the magnetic field increases if
(i) number of turns in the coil is increased
(ii) current through the coil is decreased
(iii) distance from the coil is increased
(iv) soft iron core is removed
Answer: (i) number of turns in the coil is increased

Q.16. Match the following:

List I | List II
(a) Galvanometer | (1) Detects electric current
(b) Electric motor | (2) Converts mechanical energy into electrical energy
(c) Electric generator | (3) Converts electrical energy into mechanical energy
(d) Fuse | (4) Protects circuit from overloading

(i) a-1, b-3, c-2, d-4
(ii) a-2, b-1, c-3, d-4
(iii) a-1, b-2, c-3, d-4
(iv) a-4, b-3, c-2, d-1
Answer: (i) a-1, b-3, c-2, d-4

Q.17. The split ring in an electric motor acts as a
(i) conductor
(ii) commutator
(iii) insulator
(iv) magnet
Answer: (ii) commutator

Q.18. The direction of force on a current-carrying conductor in a magnetic field is given by
(i) Right-hand thumb rule
(ii) Fleming’s right-hand rule
(iii) Fleming’s left-hand rule
(iv) Ohm’s law
Answer: (iii) Fleming’s left-hand rule

Q.19. In domestic electric circuits, appliances are connected in parallel so that
(i) the current is same in all appliances
(ii) the voltage is same across all appliances
(iii) the resistance is same
(iv) the fuse melts easily
Answer: (ii) the voltage is same across all appliances

Q.20. Assertion (A): When the magnet and coil are stationary relative to each other, no induced current is produced.
Reason (R): Electromagnetic induction occurs only when there is a change in magnetic field linked with the coil.
(i) Both A and R are true and R is the correct explanation of A
(ii) Both A and R are true but R is not the correct explanation of A
(iii) A is true but R is false
(iv) A is false but R is true
Answer: (i) Both A and R are true and R is the correct explanation of A

Q.21. When iron filings are sprinkled around a bar magnet, they arrange themselves along
(i) straight lines
(ii) concentric circles
(iii) magnetic field lines
(iv) random directions
Answer: (iii) magnetic field lines

Q.22. If the compass is moved farther away from a current-carrying straight conductor, the deflection of the needle
(i) increases
(ii) decreases
(iii) remains the same
(iv) becomes zero instantly
Answer: (ii) decreases

Q.23. The magnetic field produced by a current-carrying circular coil at its centre becomes stronger when
(i) the number of turns in the coil is increased
(ii) the radius of the coil is increased greatly
(iii) the current is reduced
(iv) the coil is made of plastic
Answer: (i) the number of turns in the coil is increased

Q.24. Assertion (A): Inside a magnet, the magnetic field lines run from south pole to north pole.
Reason (R): Magnetic field lines form closed curves.
(i) Both A and R are true and R is the correct explanation of A
(ii) Both A and R are true but R is not the correct explanation of A
(iii) A is true but R is false
(iv) A is false but R is true
Answer: (i) Both A and R are true and R is the correct explanation of A

Q.25. The device that detects the presence and direction of electric current in a circuit is
(i) ammeter
(ii) voltmeter
(iii) galvanometer
(iv) generator
Answer: (iii) galvanometer

Q.26. Match the following:

List I | List II
(a) Right-hand thumb rule | (1) Direction of magnetic field around a straight conductor
(b) Fleming’s right-hand rule | (2) Direction of induced current
(c) Fleming’s left-hand rule | (3) Direction of force on conductor
(d) Electromagnet | (4) Soft iron core with coil

(i) a-1, b-2, c-3, d-4
(ii) a-2, b-3, c-1, d-4
(iii) a-3, b-1, c-2, d-4
(iv) a-1, b-3, c-2, d-4
Answer: (i) a-1, b-2, c-3, d-4

Q.27. An electric generator works on the principle of
(i) magnetic effect of electric current
(ii) heating effect of current
(iii) electromagnetic induction
(iv) electrolysis
Answer: (iii) electromagnetic induction

Q.28. The frequency of alternating current supplied in India is
(i) 60 Hz
(ii) 100 Hz
(iii) 50 Hz
(iv) 25 Hz
Answer: (iii) 50 Hz

Q.29. The fuse wire in a domestic circuit is connected in the
(i) neutral wire
(ii) earth wire
(iii) live wire
(iv) parallel wire
Answer: (iii) live wire

Q.30. When a positively charged particle moves perpendicular to a magnetic field, the force acting on it is
(i) parallel to magnetic field
(ii) parallel to velocity
(iii) perpendicular to both velocity and magnetic field
(iv) zero
Answer: (iii) perpendicular to both velocity and magnetic field

Q.31. When the direction of current through a straight conductor is from north to south, the north pole of a compass needle placed below it deflects towards
(i) east
(ii) west
(iii) north
(iv) south
Answer: (i) east

Q.32. If the direction of current in the conductor of Q.31 is reversed, the compass needle will deflect towards
(i) east
(ii) west
(iii) north
(iv) south
Answer: (ii) west

Q.33. The magnetic field produced by a current-carrying straight conductor forms
(i) parallel straight lines
(ii) concentric circles around the conductor
(iii) radial lines
(iv) elliptical curves
Answer: (ii) concentric circles around the conductor

Q.34. Assertion (A): The magnetic field is stronger where the field lines are crowded.
Reason (R): The strength of magnetic field depends on the closeness of field lines.
(i) Both A and R are true and R is the correct explanation of A
(ii) Both A and R are true but R is not the correct explanation of A
(iii) A is true but R is false
(iv) A is false but R is true
Answer: (i) Both A and R are true and R is the correct explanation of A

Q.35. The core of an electromagnet is made of
(i) hard steel
(ii) soft iron
(iii) copper
(iv) aluminium
Answer: (ii) soft iron

Q.36. Match the following:

List I | List II
(a) AC generator | (1) Produces current that changes direction periodically
(b) DC generator | (2) Produces unidirectional current
(c) Split ring | (3) Used in DC generator
(d) Slip rings | (4) Used in AC generator

(i) a-1, b-2, c-3, d-4
(ii) a-2, b-1, c-4, d-3
(iii) a-1, b-3, c-2, d-4
(iv) a-4, b-3, c-1, d-2
Answer: (i) a-1, b-2, c-3, d-4

Q.37. The magnetic field inside a solenoid is
(i) non-uniform
(ii) uniform
(iii) zero
(iv) circular
Answer: (ii) uniform

Q.38. Short-circuiting occurs when
(i) too many appliances are connected
(ii) the live and neutral wires come into direct contact
(iii) the fuse wire melts
(iv) the earth wire is disconnected
Answer: (ii) the live and neutral wires come into direct contact

Q.39. The earth wire in domestic circuits is connected to
(i) neutral wire
(ii) live wire
(iii) a metal plate deep in the earth
(iv) fuse
Answer: (iii) a metal plate deep in the earth

Q.40. When the angle between current and magnetic field is 0°, the force on the conductor is
(i) maximum
(ii) minimum
(iii) zero
(iv) infinite
Answer: (iii) zero