Coulombs Law

Electric force between two point charges

q_1

and

q_2

separated by a distance d in air is given by

F%20%3D%20%5Cfrac%7B1%7D%7B4%20%5Cpi%20%5Cvarepsilon_0%7D%20%5Cfrac%7Bq_1%20q_2%7D%7Bd%5E2%7D%20%5C%2C%20%5C%2C%20%5C%2C%20%5C%2C%20%5C%2C%20%5C%2C

...(i) Electric force between two point charges

q_1

and

q_2

separated by a distance

d'

in a medium of relative permittivity

k

is given by

F'%20%3D%20%5Cfrac%7B1%7D%7B4%5Cpi%20E_%7B0%7Dk%20%7D%20.%20%5Cfrac%7Bq_%7B1%7Dq_%7B2%7D%7D%7Bd'%5E%7B2%7D%7D

According to question

%2C%20F%20%3D%20F'

%5Ctherefore%20%5C%2C%20%5C%2C%20%5Cfrac%7B1%7D%7B4%5Cpi%20e_%7B0%7D%7D%20%5Cfrac%7Bq_%7B1%7Dq_%7B2%7D%7D%7Bd%5E%7B2%7D%7D%20%3D%20%5Cfrac%7B%201%7D%7B4%5Cpi%20e_%7B0%7Dk%7D%20%5Cfrac%7Bq_%7B1%7Dq_%7B2%7D%7D%7Bd'%5E%7B2%7D%7D

%5Cfrac%7B1%7D%7Bd%5E%7B2%7D%20%7D%20%3D%20%5Cfrac%7B1%7D%7Bkd'%5E%7B2%7D%7D

kd'%5E%7B2%7D%20%3D%20d%5E%7B2%7D

d'%20%3D%20%5Cfrac%7Bd%7D%7B%5Csqrt%7Bk%7D%7D%20.

Chapter Questions
1 MCQs