## Parallel Plate Capacitor Formula

When two parallel plates are connected across a battery, the plates are charged and an electric field is established between them, and this setup is known as the parallel plate capacitor. The direction of the electric field is defined as the direction in which the positive test charge would flow.Capacitance is the limitation of the body to store the electric charge. Every capacitor has its capacitance. The typical parallel-plate capacitor consists of two metallic plates of area A, separated by the distance d.

The parallel plate capacitor formula is given by,

$c=k\varepsilon&space;_{0}\frac{A}{d}$

Where,

ϵo = permittivity of space (8.54 × 10−12 F/m),

k = relative permittivity of dielectric material,

d = separation between the plates,

A = area of plates.

Example 1

A parallel plate capacitor is kept in the air has an area of 0.50m2 and separated from each other by distance 0.04m. Calculate the parallel plate capacitor.

Solution:

Given:

Area A = 0.50 m2,

Distance d = 0.04 m,

relative permittivity k = 1,

ϵo = 8.54 × 10−12 F/m

The parallel plate capacitor formula is expressed by,

C = oA / d

= 8.54×10−12 × 0.50 / 0.04

= 4.27 x 10−12 / 0.04

Therefore, C = 106.75 x 10−12 F

Example 2:

Determine the area of parallel plate capacitor in the air if the capacitance is 25 nF and separation between the plates is 0.04m.

Solution:

Given:

Capacitance = 25 nF,

Distance d = 0.04 m,

Relative permittivity k = 1,

ϵo = 8.54 × 10−12 F/m

The parallel plate capacitor formula is expressed by,

C = oA / d

A = dc / kϵo

= 0.04 × 25×109 / 1×8.54×1012

A = 1 x109 / 8.54 ×1012

Therefore, area of parallel plate capacitor is 117.09 m2.