Electrostatic Potential and Capacitance - Class 12 JEE Notes

📘 Theory Notes

Electrostatic Potential: Work done to bring a unit positive charge from infinity to a point in electric field.

Potential due to point charge: V = kQ/r

Potential Energy: U = kQ₁Q₂/r

Equipotential Surface: Surface with constant potential. No work is done along these surfaces.

Capacitance: C = Q/V. Unit: Farad (F)

Parallel Plate Capacitor: C = ε₀A/d (in vacuum)

Energy Stored in Capacitor: U = ½ CV²

❓ Practice MCQs

1. Unit of potential energy is:
   A. J/s B. N/C C. Joule D. Volt
2. What is the capacitance if Q = 6C and V = 2V?
   A. 3F B. 4F C. 12F D. 2F

🧠 PYQs (JEE)

• JEE 2022: Calculate the potential at distance r from a point charge Q. [Ans: V = kQ/r]
• JEE 2020: Two capacitors in series with 3µF and 6µF. Find equivalent capacitance.