Ohm’s Law and Kirchhoff’s Rules MCQs Class 12
Ohm’s Law & Kirchhoff’s Rules – MCQs Class 12
Class: 12 | Subject: Physics |
Section: Current Electricity |
Topic: Ohm’s Law and Kirchhoff’s Rules
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. Ohm’s Law states that:
Answer: B
At constant temperature, voltage is directly proportional to current.
At constant temperature, voltage is directly proportional to current.
2. Ohm’s law is valid when:
Answer: B
Law holds only under constant physical conditions.
Law holds only under constant physical conditions.
3. Slope of V–I graph gives:
Answer: B
Slope = V/I = Resistance.
Slope = V/I = Resistance.
4. Unit of resistance:
Answer: C
SI unit is Ohm.
SI unit is Ohm.
5. Junction rule is based on:
Answer: B
Total current entering equals leaving.
Total current entering equals leaving.
6. Loop rule based on:
Answer: B
Energy conservation in closed loop.
Energy conservation in closed loop.
7. Algebraic sum of EMFs in loop is:
Answer: B
As per Kirchhoff’s loop law.
As per Kirchhoff’s loop law.
8. Kirchhoff’s laws applicable to:
Answer: C
Valid for all circuits.
Valid for all circuits.
9. Wheatstone bridge works on:
Answer: C
Uses both principles.
Uses both principles.
10. Balanced bridge current through galvanometer:
Answer: C
No potential difference.
No potential difference.
11. Non‑ohmic device example:
Answer: B
V–I not linear.
V–I not linear.
12. Resistance ↑ with temperature for:
Answer: A
Due to lattice vibrations.
Due to lattice vibrations.
13. Current divider rule uses:
Answer: C
Combination analysis.
Combination analysis.
14. Potential drop sign convention:
Answer: B
Drop taken negative.
Drop taken negative.
15. Source EMF rise sign:
Answer: A
Energy supplied.
Energy supplied.
16. Ammeter resistance:
Answer: B
To allow current.
To allow current.
17. Voltmeter resistance:
Answer: B
Draws negligible current.
Draws negligible current.
18. Equivalent resistance series:
Answer: A
Add directly.
Add directly.
19. Parallel resistance always:
Answer: B
Less than smallest.
Less than smallest.
20. Kirchhoff’s laws fail at:
Answer: A
Due to inductive/capacitive effects.
Due to inductive/capacitive effects.