Class 12 Physics - Electrostatic Potential and Capacitance

A set of vocabulary flashcards covering the core formulas and concepts of Class 12 Physics Chapter 2: Electrostatic Potential and Capacitance.

Potential due to point charge

$$V = \frac{kQ}{r}$$

Potential energy

$$U = \frac{k q_1 q_2}{r}$$

Electric field and potential relation

$E = -\frac{dV}{dr}$ (or $E = -\nabla V$)

Capacitance

$$C = \frac{Q}{V}$$

Parallel plate capacitor

$$C = \frac{\epsilon_0 A}{d}$$

Parallel plate capacitor with dielectric

$$C = \frac{K \epsilon_0 A}{d}$$

Capacitors in Series

$$\frac{1}{C_{eq}} = \sum (\frac{1}{C})$$

Capacitors in Parallel

$$C_{eq} = \sum C$$

Energy stored in a capacitor

$$U = \frac{1}{2} CV^2 = \frac{Q^2}{2C} = \frac{1}{2} QV$$

Energy density

$$u = \frac{1}{2} \epsilon E^2$$

Electric field and equipotential surfaces

Electric field is perpendicular to equipotential surfaces.

Electrostatic conductor property

Inside an electrostatic conductor, $E = 0$ and potential is constant.

Effect of dielectric on capacitance

A dielectric increases capacitance by factor $K$.