FUNDAMENTALS

ELECTROSTATICS:


All bodies are able to take a charge of electricity, and this is known as

static electricity. The charge on the body is measured by means of

the force between the two charges, this force following the inverse square law

( i.e ) the force is proportional to the product of the charges and inversely

Proportional to the square of the distance between them).

This may be written as F=q1q2/4╥ﻉ○d² N

Where q1 and q2 are the charges in coulombs and d the distance in metres- the

Space in between the charges being either air or a vacuum with permittivity ﻉ○.

N is Newtons.

If the two charged bodies are separated by some other medium the force acting

may be different, depending upon the relative permittivity of the dielectric

between the two charged bodies.

The relative permittivity is termed as dielectric constant.

In this case force F= q1q2/ 4╥ﻉŗﻉ○ d² N

whereﻉŗ is the constant for the particular dielectric. For Air or Vacuum the value

ofﻉŕ s Unity..