### Electrostatics

Electrostatics is study of stationary electric charges

**Characteristic Of Charge**

- Like charges repel one another; that is, positive repels positive and negative repels negative.
- Charge and conserved
- Motion does not affect charge

**Coulomb's Charge**

Coulomb's law gives the magnitude of the electrostatic force ( F) between two charges:

$ F = {{kq_1q_2} \over {r^2}}$Electric Field Intensity

the Force experienced by a unit positive charge placed at that point

$ E = {1 \over 4πε_0} {Q \over r^2}$**Gauss’s theorem **

total electric flux through any closed surface surrounding a charge is equal to the net positive charge enclosed by that surface.

**Electrostatic Potential **The electrostatic potential at any point in an electric field is equal to the amount of work done per unit positive test charge or in bringing the unit positive test charge from infinite to that point, against the electrostatic force without acceleration.

It is SI Unit is Volt (V) and dimension formula is [ML^{2}T^{-3}A^{-1}].

Dielectric Strength: It is the minimum field intensity that should be applied to break down the insulating property of insulator.

### Capacitor and Capacitance

Capacitor is an electronic component which have ability to store energy in form of electric energy

The Capacitance of capacitor connected in series can be calculated as :

$ C_{total} = {1 \over {{1 \over {C_1} } + {1 \over {C_2} } + {1 \over {C_3 } } + ... }}$

Parallel Capacitance

$ C_{total} = C_1 + C_2 + ... + C_n $

**Energy stored in a capacitor**

The work done on moving a positive charge from a negative conductor to a positive conductor against the repulsive forces is known as Energy Stored in Capacitor.

It can be calculated as

$ U = {{1 \over 2} {CV^2}}$