Biot–Savart Law & Ampere’s Law MCQs
Biot–Savart Law & Ampere’s Law – MCQs
Class: 12 | Subject: Physics |
Section: Magnetic Effects of Current & Magnetism |
Topic: Biot–Savart Law & Ampere’s Law
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. Biot–Savart law gives magnetic field due to:
Answer: B
It calculates magnetic field produced by a small current‑carrying element.
It calculates magnetic field produced by a small current‑carrying element.
2. Magnetic field dB ∝
Answer: D
dB ∝ I dl sinθ / r².
dB ∝ I dl sinθ / r².
3. Unit of magnetic field:
Answer: A
SI unit is Tesla.
SI unit is Tesla.
4. Direction given by:
Answer: B
Thumb → current, fingers → field.
Thumb → current, fingers → field.
5. Field at centre of circular loop:
Answer: A
B = μ₀I/2R.
B = μ₀I/2R.
6. Long straight wire field ∝
Answer: C
B = μ₀I/2πr.
B = μ₀I/2πr.
7. Ampere’s law relates:
Answer: A
Integral form relation.
Integral form relation.
8. Ampere’s circuital law valid for:
Answer: A
Used in symmetric current distributions.
Used in symmetric current distributions.
9. Field inside solenoid:
Answer: B
B = μ₀nI.
B = μ₀nI.
10. Outside long solenoid field:
Answer: B
Nearly zero.
Nearly zero.
11. Toroid field confined in:
Answer: A
Closed magnetic path.
Closed magnetic path.
12. Toroid field formula:
Answer: A
Derived via Ampere’s law.
Derived via Ampere’s law.
13. Biot–Savart vs Coulomb law similarity:
Answer: D
Mathematical analogy.
Mathematical analogy.
14. Magnetic field lines form:
Answer: B
No monopoles.
No monopoles.
15. Field superposition applies to:
Answer: C
Vector addition principle.
Vector addition principle.
16. Field at loop centre increases with:
Answer: D
B ∝ NI/R.
B ∝ NI/R.
17. Ampere’s law derived from:
Answer: A
Integral simplification.
Integral simplification.
18. Magnetic permeability unit:
Answer: A
μ₀ unit henry per metre.
μ₀ unit henry per metre.
19. Field strongest near:
Answer: B
B ∝ 1/r.
B ∝ 1/r.
20. Ampere’s law fails for:
Answer: A
Needs Maxwell correction.
Needs Maxwell correction.
