Chapter-4 Moving Charges and Magnetism — Online MCQ Test
PHYSICS · CLASS 12 SECOND PUC · Karnataka State Board
Practice Chapter-4 Moving Charges and Magnetism with a free chapter-wise online MCQ test.
This chapter covers: Biot-Savart law - Ampere's law - Lorentz force - magnetic field - solenoid - galvanometer - parallel currents.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter-4 Moving Charges and Magnetism — Important Questions & Answers
The Biot-Savart law gives the magnetic field due to which of the following?
- A. A stationary point charge
- B. A current-carrying conductor
- C. A permanent magnet
- D. A charged particle at rest
Answer: B. A current-carrying conductor
The Biot-Savart law specifically describes the magnetic field produced by a current-carrying conductor or a moving charge.
The Biot-Savart law specifically describes the magnetic field produced by a current-carrying conductor or a moving charge.
What is the SI unit of magnetic field strength?
- A. Ampere (A)
- B. Tesla (T)
- C. Weber (Wb)
- D. Henry (H)
Answer: B. Tesla (T)
Tesla (T) is the SI unit of magnetic field strength or magnetic flux density (B).
Tesla (T) is the SI unit of magnetic field strength or magnetic flux density (B).
The magnetic field inside a long solenoid with n turns per unit length carrying current I is given by:
- A. B = μ₀I
- B. B = μ₀nI
- C. B = μ₀I/n
- D. B = nI/μ₀
Answer: B. B = μ₀nI
The magnetic field inside a solenoid is B = μ₀nI, where n is the number of turns per unit length and I is the current.
The magnetic field inside a solenoid is B = μ₀nI, where n is the number of turns per unit length and I is the current.
A charged particle moves in a circular path in a uniform magnetic field. The radius of the circular path depends on:
- A. Only the charge of the particle
- B. Only the magnetic field strength
- C. The momentum of the particle and the magnetic field strength
- D. Only the velocity of the particle
Answer: C. The momentum of the particle and the magnetic field strength
The radius r = mv/(qB), which depends on the particle's momentum (mv) and the magnetic field strength B.
The radius r = mv/(qB), which depends on the particle's momentum (mv) and the magnetic field strength B.
A rectangular loop ABCD with sides 3 m and 4 m carries current 5 A. It is placed in a uniform magnetic field of 2 T perpendicular to the plane. The torque on the loop is:
- A. Zero
- B. 60 N·m
- C. 120 N·m
- D. Cannot be determined without angle information
Answer: A. Zero
For a rectangular loop in a uniform field perpendicular to its plane, the forces on opposite sides cancel, giving zero net torque.
For a rectangular loop in a uniform field perpendicular to its plane, the forces on opposite sides cancel, giving zero net torque.