Moving Charges and Magnetism MCQs Class 12 Physics
Moving Charges and Magnetism – MCQs Class 12 Physics
Class: 12 | Subject: Physics |
Section: Magnetic Effects of Current & Magnetism |
Topic: Moving Charges and Magnetism
Based on: NCERT Syllabus | CBSE Board Examination Standard
Based on: NCERT Syllabus | CBSE Board Examination Standard
Instructions: These Multiple Choice Questions (MCQs) are designed strictly as per the NCERT syllabus, making them ideal for CBSE Class 12 Board Examination preparation.
1. Magnetic force on a moving charge is given by:
Answer: B
Lorentz force formula F = qvB sinθ.
Lorentz force formula F = qvB sinθ.
2. Force is maximum when θ =
Answer: D
Sin90° = 1 → maximum force.
Sin90° = 1 → maximum force.
3. Unit of magnetic field:
Answer: A
SI unit is Tesla.
SI unit is Tesla.
4. Direction of force determined by:
Answer: A
Used for force on current conductor.
Used for force on current conductor.
5. Force on stationary charge in magnetic field:
Answer: B
v = 0 → F = 0.
v = 0 → F = 0.
6. Radius of circular path ∝
Answer: D
r = mv/qB.
r = mv/qB.
7. Cyclotron works on:
Answer: C
Acceleration by E, bending by B.
Acceleration by E, bending by B.
8. Time period in cyclotron independent of:
Answer: A
T = 2πm/qB.
T = 2πm/qB.
9. Biot–Savart law gives:
Answer: B
Field due to current element.
Field due to current element.
10. Field at centre of circular loop ∝
Answer: D
B = μ₀NI/2R.
B = μ₀NI/2R.
11. Long straight wire field ∝
Answer: C
B = μ₀I/2πr.
B = μ₀I/2πr.
12. Ampere’s law relates:
Answer: A
Magnetic field with current.
Magnetic field with current.
13. Solenoid field inside is:
Answer: B
Uniform parallel lines.
Uniform parallel lines.
14. Force between parallel currents:
Answer: C
Same attract, opposite repel.
Same attract, opposite repel.
15. Torque on current loop:
Answer: B
Magnetic dipole torque.
Magnetic dipole torque.
16. Magnetic dipole moment unit:
Answer: A
I × area.
I × area.
17. Moving coil galvanometer based on:
Answer: A
Force on current loop.
Force on current loop.
18. Radial magnetic field ensures:
Answer: C
θ = 90° always.
θ = 90° always.
19. Lorentz force includes:
Answer: C
Total force = q(E + vB).
Total force = q(E + vB).
20. Magnetic field does no work because:
Answer: C
Work = F·v = 0.
Work = F·v = 0.
