Chapter 9: Electromagnetic Induction — Online MCQ Test
PHYSICS · CLASS 12 INTERMEDIATE 2 YEAR · Telangana State Board
Practice Chapter 9: Electromagnetic Induction with a free chapter-wise online MCQ test.
This chapter covers: Focusing on induced currents this chapter details Faraday laws Lenz Law eddy currents self and mutual inductance and ac generator principles..
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 9: Electromagnetic Induction — Important Questions & Answers
According to Faraday's first law of electromagnetic induction, when is emf induced in a circuit?
- A. Whenever magnetic flux linked with the circuit changes
- B. Whenever the circuit has a battery connected
- C. Whenever the circuit resistance changes
- D. Whenever the current in the circuit is zero
Answer: A. Whenever magnetic flux linked with the circuit changes
An emf is induced only when the magnetic flux through a circuit changes with time. This is the basic statement of Faraday's first law.
An emf is induced only when the magnetic flux through a circuit changes with time. This is the basic statement of Faraday's first law.
The SI unit of mutual inductance is:
- A. weber
- B. henry
- C. tesla
- D. ampere
Answer: B. henry
Mutual inductance is measured in henry (H), the same unit as self-inductance. It relates induced emf to the rate of change of current.
Mutual inductance is measured in henry (H), the same unit as self-inductance. It relates induced emf to the rate of change of current.
A coil is moved faster into a magnetic field. What happens to the induced emf?
- A. It decreases
- B. It remains zero
- C. It increases
- D. It becomes independent of motion
Answer: C. It increases
A faster motion changes magnetic flux more rapidly. By Faraday's law, the induced emf increases with the rate of change of flux.
A faster motion changes magnetic flux more rapidly. By Faraday's law, the induced emf increases with the rate of change of flux.
A square coil is placed in a magnetic field perpendicular to its plane. If the field strength is doubled in the same time interval, the induced emf will:
- A. be halved
- B. double
- C. remain unchanged
- D. become zero
Answer: B. double
Induced emf is proportional to the rate of change of magnetic flux. Doubling the field strength doubles the change in flux for the same time interval.
Induced emf is proportional to the rate of change of magnetic flux. Doubling the field strength doubles the change in flux for the same time interval.
A coil of resistance R is connected to a galvanometer. When a bar magnet is pushed toward the coil, the galvanometer shows a deflection. If the same magnet is kept stationary inside the coil, the deflection becomes zero. The best explanation is:
- A. Magnetic field inside the coil becomes zero when the magnet stops
- B. Current can flow only if resistance changes
- C. Induced emf exists only during change in magnetic flux
- D. Galvanometer works only with alternating current
Answer: C. Induced emf exists only during change in magnetic flux
Deflection occurs only when the magnetic flux linked with the coil changes. Once the magnet is stationary, the flux is constant and no emf is induced.
Deflection occurs only when the magnetic flux linked with the coil changes. Once the magnet is stationary, the flux is constant and no emf is induced.