Faraday’s and Lenz’s Law MCQs with Explanations
Faraday’s & Lenz’s Law – MCQs with Explanations
Class: 12 | Subject: Physics |
Section: Electromagnetic Induction & Alternating Current |
Topic: Faraday’s and Lenz’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. Faraday’s First Law states that emf is induced when:
Answer: B
Induced emf appears whenever magnetic flux linked with a circuit changes.
Induced emf appears whenever magnetic flux linked with a circuit changes.
2. Faraday’s Second Law gives magnitude proportional to:
Answer: B
e ∝ dΦ/dt.
e ∝ dΦ/dt.
3. SI unit of induced emf:
Answer: A
Measured in volts.
Measured in volts.
4. Negative sign in Faraday’s law indicates:
Answer: B
Opposition to flux change.
Opposition to flux change.
5. Lenz’s law is based on conservation of:
Answer: B
Prevents creation of energy.
Prevents creation of energy.
6. Induced current opposes:
Answer: B
Lenz’s law statement.
Lenz’s law statement.
7. Magnetic flux unit:
Answer: A
Φ unit Weber.
Φ unit Weber.
8. Flux Φ =
Answer: B
Dot product relation.
Dot product relation.
9. Maximum flux when θ =
Answer: A
cos0° = 1.
cos0° = 1.
10. Induced emf zero when:
Answer: D
No flux change.
No flux change.
11. Generator based on:
Answer: A
Mechanical → electrical.
Mechanical → electrical.
12. Direction found by:
Answer: A
Generator rule.
Generator rule.
13. Eddy currents arise due to:
Answer: A
Induction in bulk metal.
Induction in bulk metal.
14. Lenz’s law ensures:
Answer: B
Opposition prevents free energy.
Opposition prevents free energy.
15. Mutual induction occurs in:
Answer: A
Changing current induces emf.
Changing current induces emf.
16. Self induction emf ∝
Answer: A
e = −L di/dt.
e = −L di/dt.
17. Inductance unit:
Answer: A
SI unit Henry.
SI unit Henry.
18. Transformer uses:
Answer: B
Flux linkage principle.
Flux linkage principle.
19. Back emf due to:
Answer: A
Opposes supply.
Opposes supply.
20. Induced emf maximum when flux change:
Answer: B
Greater dΦ/dt.
Greater dΦ/dt.
