Important Questions for Class 12 Physics Chapter 2 focus on Electrostatic Potential and Capacitance, a high-weightage chapter from Electrostatics. As the Class 12 Physics board exam is scheduled for February 20, 2026, students must prioritize derivations, formulas, and numerical practice from this chapter.
The chapter explains electric potential, potential difference, equipotential surfaces, capacitance, capacitors in series and parallel, energy stored in a capacitor, and dielectric materials.
Most Repeated Questions from Electrostatic Potential And Capacitance
These questions frequently appear in 3-mark and 5-mark formats in board exams.
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Define electric potential and derive its expression due to a point charge.
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Derive the expression for potential due to an electric dipole.
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Define capacitance and derive capacitance of a parallel plate capacitor.
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Explain combination of capacitors in series and parallel.
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Derive expression for energy stored in a capacitor.
Electrostatic Potential And Capacitance Class 12 Important Questions
The chapter Electrostatic Potential and Capacitance requires conceptual clarity along with strong mathematical application. Students should thoroughly practice Electrostatic Potential And Capacitance Class 12 Solutions, especially derivations related to potential due to point charge, electric dipole, and energy stored in a capacitor.
Below are Electrostatic Potential And Capacitance Class 12 Question Answers for board exam preparation:
1. Two plates of a parallel plate capacitor are 1 cm apart and potential difference between them is 10 V. The electric field between the plates is [Foreign 2017, Delhi 2002]
2. A 10 F capacitor is charged by a battery of e.m.f. 100 V. The electrostatic energy stored in the capacitor is [Delhi 2021]
(A) 0.5 J
(B) 0.05 J
(C) 0.5 mJ
(D) 0.05 mJ
3. Two capacitors of capacitances 3 F and 6 F are charged to a potential of 12 V each. They are now connected to each other, with the positive plate of each joined to the negative plate of the other. The potential difference across each capacitor will be [OD 2002]
(A) 6 V
(B) 4 V
(C) 3 V
(D) Zero
4. 
(A) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(B) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
(C) Assertion is correct but Reason is incorrect.
(D) Assertion is incorrect but Reason is correct.
Sol. (C)
Sol. Charge stored on the two plates are +Q and –Q Q + (–Q) = 0 and hence Assertion is correct.
The field however, outside the plates is zero.
5. Assertion (A): Equal amount of positive and negative charges are distributed uniformly on two halves of a thin circular ring as shown in figure. The resultant electric field at the centre O of the ring is along OC.
Reason (R): It is so because the net potential at O is not zero. [OD 2024]
(A) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(B) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
(C) Assertion is correct but Reason is incorrect.
(D) Assertion is incorrect but Reason is correct.
Sol. (C)
The net field at point O is along OC due to vector sum of all the fields. Hence assertion is correct. The potential at centre of ring will be zero. Hence reason is incorrect. Thus option (C) is correct
6. Give two factors which affect capacitance of a conductor. [OD 2012]
Sol. 1. material of conductor. 2. Cross-section area of conductor.
7. Why is there no work done in moving a charge from one point to another on an equipotential surface? [Delhi 2018]
8. Why does the electric field inside a dielectric decrease when it is placed in an external electric field? [Comp 2016]
10. A slab of material of dielectric constant K has the same area as that of the plates of a parallel plate capacitor but has the thickness d/2, where d is the separation between the plates. Find out the expression for its capacitance when the slab is inserted between the plates of the capacitor. [Delhi 2021]
Important Numericals from Electrostatic Potential And Capacitance
Numerical-based questions are scoring when practiced thoroughly. Revise:
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Potential difference calculations.
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Capacitance of parallel plate capacitor problems.
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Energy stored in capacitor numericals.
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Series and parallel capacitor combination problems.
Regular practice of Electrostatic Potential And Capacitance Class 12 Solutions improves speed and reduces calculation errors before the CBSE 12th Physics board exam.