Electromagnetism MCQs

1. Magnetic force acting on a unit positive charge moving perpendicular to the magnetic field with a unit velocity is called

A. Magnetic flux

B. Magnetic field intensity

C. Magnetic induction

D. Self-inductance

✅ The correct answer is option C.

2. A current carrying conductor is placed in a uniform magnetic field parallel to it. The magnetic force experienced by the conductor is

A. F=1/B

B. F=1/Bsinθ

C. F/0

D. F=1/Bcosθ

✅ The correct answer is option C.

3. What is the value of the current in a wire of 10cm long at the right angle to a uniform magnetic field of 0.5 Weber/m2 when the force acting on the wire is 5N?

A. 1A

B. 10A

C. 100A

D. 1000A

✅ The correct answer is option C.

4. When a particle of charge q and mass m enters into a uniform magnetic field B moving with a velocity v perpendicular to the direction for the field it describes a circular path of radius

A. R=qB/mV

B. R=mV/qB

C. R=qmV/B

D. R=qmB/V

✅ The correct answer is option B.

5. A particle of mass m and charge Q moving with velocity V enters the region of a uniform magnetic field at right angle to the direction of its motion. How does its kinetic energy get affected?

A. Its kinetic energy will be affected

B. Its kinetic energy won’t be affected

C. It’s all energy won’t be affected

D. Its kinetic force won’t be affected

✅ The correct answer is option B.

6. Two parallel wires carrying currents in the opposite directions

A. Repel each other

B. Attract each other

C. Have no effect upon each other

D. They cancel out their individual magnetic fields

✅ The correct answer is option A.

7. A magnetic compass will be deflected if it is kept near a

A. Charge in motion

B. Charge at rest

C. Both

D. None

✅ The correct answer is option A.

8. A magnetic field

A. Always exerts a force on a charged particle

B. Never exerts a force on a charged particles

C. Exerts a force if the charged particle is moving in the direction of the magnetic field lines

D. Exerts a force if the charged particle is moving perpendicular to the magnetic field lines

✅ The correct answer is option D.

9. A moving coil galvanometer of resistance 100Ω gives half scale deflection for a current of 20mA. What will be the potential difference across it?

A. 4 volt

B. 5 volt

C. 2 volt

D. 0.4 volt

✅ The correct answer is option C.

10. Which one of the following material is most suitable for making core of an electromagnet?

A. Air

B. Steel

C. Cu-Ni alloy

D. Soft iron

✅ The correct answer is option D.