# Capacitance Formula

## Capacitance Formula

Capacitance is used to describe how much charge any conductor can hold. It represents the ratio of the charge flowing across the conductor to the potential applied. Capacitors are the conductors used for holding charges.

Capacitance is the ability of a substance to store an electrical charge. Any object that can be electrically charged shows capacitance. A parallel-plate capacitor is the common form of energy storage device. Capacitance is exhibited by a parallel plate arrangement and defined in terms of charge storage. When a capacitor is charged completely, there is a potential difference between its plates, and larger the area of the plates and/or smaller the distance between them, greater will be the charge of the capacitor and greater will be its Capacitance.

Capacitance Formula is expressed as

C = Q / V

Where,

Q denotes the charge of the conductor,

V denotes the potential applied across the conductor and

C is proportionality constant, called capacitance

If the capacitors are connected in series, the capacitance formula is expressed by

If capacitors are connected in parallel, the capacitance formula is expressed by

Where C1,C2,C3…….Cn are the capacitors and Capacitance is expressed in Farads

Example 1

Determine the capacitance of the capacitor if 5 coulomb of charge is flowing and 2V of potential is applied.

Solution

Given parameters are

Charge Q is 5 C,

Voltage applied V is 2 V

the Capacitance formula is given by

C = Q / V

= 5 / 2

= 2.5 F

Example 2

Determine the capacitance if capacitors 6 F and 5 F are connected

(i) In series and

(ii) In parallel

Solution

The capacitance in series formula is given by

Cs = 1/C1 + 1/C2

= C1+C2 / C1C2

= 6+5 / 30

= 0.367 F

The capacitance in parallel formula is given by

Cp = C1 + C2

= 6 + 5

= 11 F

#### Practise This Question

A disc rotates about its axis with a constant angular acceleration of 4 rads2. Find the radial and tangential accelerations of a particle at a distance of 1 cm from the axis at the end of the first second after the disc starts rotating.