Capacitors & Dielectrics MCQs for Board Exams
Capacitors & Dielectrics – MCQs for Board Exams
Class: 12 | Subject: Physics |
Section: Electrostatics |
Topic: Capacitors & Dielectrics
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. Capacitance is defined as:
Answer: B
Capacitance is charge stored per unit potential difference.
Capacitance is charge stored per unit potential difference.
2. SI unit of capacitance:
Answer: C
1 Farad = 1 Coulomb/Volt.
1 Farad = 1 Coulomb/Volt.
3. Capacitance of parallel plate capacitor depends on:
Answer: D
C = εA/d → depends on all three.
C = εA/d → depends on all three.
4. Inserting dielectric increases capacitance by:
Answer: B
C = KC₀.
C = KC₀.
5. Energy stored in capacitor:
Answer: B
Standard energy formula.
Standard energy formula.
6. Dielectric constant is:
Answer: B
Ratio of capacitances.
Ratio of capacitances.
7. Series capacitance:
Answer: B
Equivalent decreases.
Equivalent decreases.
8. Parallel capacitance:
Answer: B
Adds directly.
Adds directly.
9. Electric field in dielectric:
Answer: B
Reduced by factor K.
Reduced by factor K.
10. Polar molecules example:
Answer: C
Water is polar.
Water is polar.
11. Non‑polar molecule:
Answer: B
Symmetrical charge distribution.
Symmetrical charge distribution.
12. Breakdown occurs due to:
Answer: B
Ionization of dielectric.
Ionization of dielectric.
13. Capacitance of isolated sphere ∝
Answer: B
C = 4πϵ₀R.
C = 4πϵ₀R.
14. Charge remains constant when:
Answer: B
No external supply.
No external supply.
15. Potential remains constant when:
Answer: A
Battery fixes voltage.
Battery fixes voltage.
16. Energy stored region:
Answer: C
Energy in electric field.
Energy in electric field.
17. Dielectric reduces:
Answer: B
Polarization opposes field.
Polarization opposes field.
18. Capacitance independent of:
Answer: A
Only geometry & medium matter.
Only geometry & medium matter.
19. Combination giving max capacitance:
Answer: B
Capacitances add.
Capacitances add.
20. Dielectric strength measures:
Answer: C
Maximum field before breakdown.
Maximum field before breakdown.