MCQ Questions of Electromagnetic Induction | Physics

Q1) Two coils are placed closed to each other. The mutual inductance of the pair of coils depends upon

(A) the rate at which currents are changing in the two coils.

(B) relative position and orientation of two coils.

(C) the material of the wires of the coils.

(D) the currents in the two coils.

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Q2) When current in a coil changes from 5 A to 2 A in 0.1 s, average voltage of 50 V is produced. The self-inductance of the coil is

(A) 1.67 H

(B) 6 H

(C) 3 H

(D) 0.67 H

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Q3) A coil having 500 sq. loops of side 10 cm is placed normal to magnetic flux which increases at a rate of 1 T/s. The induced emf is

(A) 0.1 V

(B) 0.5 V

(C) 1 V

(D) 5 V

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Q4) A coil of 100 turns carries a current of 5 mA and creates a magnetic flux of 10-5 weber. The inductance is

(A) 0.2 mH

(B) 2.0 mH

(C) 0.02 mH

(D) 0.002 H

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Q5) Lenz’s law of electromagnetic induction is as per law of conservation of

(A) energy

(B) charge

(C) momentum angular

(D) electromotive force

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Q6) The current flows from A to B is as shown in the figure. The direction of the induced current in the loop is

(A) clockwise

(B) anticlockwise

(C) straight line

(D) no induced e.m.f. produced

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Q7) The north pole of a long bar magnet was pushed slowly into a short solenoid connected to a short galvanometer. The magnet was held stationary for a few seconds with the north pole in the middle of the solenoid and then withdrawn rapidly. The maximum deflection of the galvanometer was observed when the magnet was

(A) moving towards the solenoid

(B) moving into the solenoid

(C) at rest inside the solenoid

(D) moving out of the solenoid

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Q8) Faraday’s laws are consequence of the conservation of

(A) charge

(B) energy

(C) magnetic field

(D) both B and C

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Q9) Two identical coaxial coils P and Q carrying equal amount of current in the same direction are brought nearer. The current in

(A) P increases while in Q decreases

(B) Q increases while in P decreases

(C) both P and Q increases

(D) both P and Q decreases

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Q10) Which of the following does not use the application of eddy current?

(A) Electric power meters

(B) Induction furnace

(C) LED lights

(D) Magnetic brakes in trains

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Q11) If number of turns in primary and secondary coils is increased to two times each, the mutual inductance

(A) becomes 4 times

(B) becomes 2 times

(C) becomes A times

(D) remains unchanged 4

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Q12) When the rate of change oic current is unity, the induced emf is equal to

(A) thickness of coil

(B) number of turns in coil

(C) coefficient of self inductance

(D) total flux linked with coil

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Q13) Two inductors of inductance .L each are connected in series with opposite? magnetic fluxes. The resultant inductance is
(Ignore mutual inductance)

(A) zero

(B) L

(C) 2L

(D) 3L

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Q14) A cylindrical bar magnet is rotated about its axis (Figure). A wire is connected from the axis and is made to touch the cylindrical surface through a contact. Then

(A) a direct current flows in the ammeter A

(B) no current flows through the ammeter A

(C) an alternating sinusoidal current flows through the ammeter A with a time period T = 2πω

(D) a time varying non-sinosoidal current flows through the ammeter

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Q15) There are two coils A and B as shown in Figure. A current starts flowing in B as shown, when A is moved towards B and stops when A stops moving. The current in A is counterclockwise. B is kept stationary when A moves. We can infer that

(A) there is a constant current in the clockwise direction in A.

(B) there is a varying current in A

(C) there is no current in A.

(D) there is a constant current in the counterclockwise direction in A.

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Q16) Same as question 4 except the coil A is made to rotate about a vertical axis (Figure). No current flows in B if A is at rest. The current in coil A, when the current in B (at t = 0) is counterclockwise and the coil A is as shown at this instant, t = 0, is

(A) constant current clockwise.

(B) varying current clockwise

(C) varying current counterclockwise.

(D) constant current counterclockwise.

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Q17) An e.m.f is produced in a coil, which is not connected to an external voltage source. This is not due to

(A) the coil being in a time varying magnetic field.

(B) the coil moving in a time varying magnetic field.

(C) the coil moving in a constant magnetic field.

(D) the coil is stationary in external spatially varying magnetic field, which does not change with time.

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Q18) Identify the wrong statement.

(A) Eddy currents are produced in a steady magnetic field.

(B) Eddy currents can be minimized by using laminated core

(C) Induction furnace uses eddy current to produce heat.

(D) Eddy current can be used to produce braking force in moving trains.

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Q19) A metal plate can be heated by

(A) passing either a direct or alternating current through the plate.

(B) placing in a time varying magnetic field.

(C) placing in a space varying magnetic field, but does not vary with time.

(D) both A and B are correct.

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Q20) The north pole of a bar magnet is rapidly introduced into a solenoid at one end (say A). Which of the following statements correctly depicts the phenomenon taking place?

(A) No induced emf is developed.

(B) The end A of the solenoid behaves like a south pole.

(C) The end A of the solenoid behaves like north pole.

(D) The end A of the solenoid acquires positive potential.

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Q21) In the given figure current from A to B in the straight wire is decreasing. The direction of induced current in the loop is A

(A) clockwise

(B) anticlockwise

(C) changing

(D) nothing can be said

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Q22) There is a uniform magnetic field directed perpendicular and into the plane of the paper. An irregular shaped conducting loop is slowly changing into a circular loop in the plane of the paper. Then

(A) current is induced in the loop in the anti-clockwise direction.

(B) current is induced in the loop in the clockwise direction.

(C) ac is induced in the loop.

(D) no current is induced in the loop.

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Q23) Which of the following statements is not correct?

(A) Whenever the amount of magnetic flux linked with a circuit changes, an emf is induced in circuit.

(B) The induced emf lasts so long as the change in magnetic flux continues.

(C) The direction of induced emf is given by Lenz’s law.

(D) Lenz’s law is a consequence of the law of conservation of momentum.

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Q24) A solenoid is connected to a battery so that a steady current flows through it. If an iron core is inserted into the solenoid, the current will

(A) increase

(B) decrease

(C) remain same

(D) first increase then decrease

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Q25) Lenz’s law is a consequence of the law of conservation of

(A) charge

(B) energy

(C) induced emf

(D) induced current

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Q26) Direction of current induced in a wire moving in a magnetic field is found using

(A) Fleming’s left hand rule

(B) Fleming’s right hand rule

(C) Ampere’s rule

(D) Right hand clasp rule

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12th Class - Physics | Chapter: Electromagnetic Induction MCQs

Q1) Two coils are placed closed to each other. The mutual inductance of the pair of coils depends upon

Q2) When current in a coil changes from 5 A to 2 A in 0.1 s, average voltage of 50 V is produced. The self-inductance of the coil is

Q3) A coil having 500 sq. loops of side 10 cm is placed normal to magnetic flux which increases at a rate of 1 T/s. The induced emf is

Q4) A coil of 100 turns carries a current of 5 mA and creates a magnetic flux of 10-5 weber. The inductance is

Q5) Lenz’s law of electromagnetic induction is as per law of conservation of

Q6) The current flows from A to B is as shown in the figure. The direction of the induced current in the loop is

Q8) Faraday’s laws are consequence of the conservation of

Q9) Two identical coaxial coils P and Q carrying equal amount of current in the same direction are brought nearer. The current in

Q10) Which of the following does not use the application of eddy current?

Q11) If number of turns in primary and secondary coils is increased to two times each, the mutual inductance

Q12) When the rate of change oic current is unity, the induced emf is equal to

Q13) Two inductors of inductance .L each are connected in series with opposite? magnetic fluxes. The resultant inductance is (Ignore mutual inductance)

Q14) A cylindrical bar magnet is rotated about its axis (Figure). A wire is connected from the axis and is made to touch the cylindrical surface through a contact. Then

Q15) There are two coils A and B as shown in Figure. A current starts flowing in B as shown, when A is moved towards B and stops when A stops moving. The current in A is counterclockwise. B is kept stationary when A moves. We can infer that

Q16) Same as question 4 except the coil A is made to rotate about a vertical axis (Figure). No current flows in B if A is at rest. The current in coil A, when the current in B (at t = 0) is counterclockwise and the coil A is as shown at this instant, t = 0, is

Q17) An e.m.f is produced in a coil, which is not connected to an external voltage source. This is not due to

Q18) Identify the wrong statement.

Q19) A metal plate can be heated by

Q20) The north pole of a bar magnet is rapidly introduced into a solenoid at one end (say A). Which of the following statements correctly depicts the phenomenon taking place?

Q21) In the given figure current from A to B in the straight wire is decreasing. The direction of induced current in the loop is A

Q22) There is a uniform magnetic field directed perpendicular and into the plane of the paper. An irregular shaped conducting loop is slowly changing into a circular loop in the plane of the paper. Then

Q23) Which of the following statements is not correct?

Q24) A solenoid is connected to a battery so that a steady current flows through it. If an iron core is inserted into the solenoid, the current will

Q25) Lenz’s law is a consequence of the law of conservation of

Q26) Direction of current induced in a wire moving in a magnetic field is found using

Subjects (12th Class)

Chapters (Physics)