# COULOMB’S LAW

# COULOMB’S LAW:

Coulomb law tell about interaction of charges. as we know that same charges repel each other and unlike charges attract each other but with how much force they repel or attract each other. This concept was given by coulomb

Let consider two charges +Q1 and +Q2 and the distance from centre of first charge to the centre of second charge is R. As these charges are same so Q2 charge exert force on Q1 and Q1 charge exert force on Q2. Coulomb sir say that these forces are same in magnitude but apposite in direction. He also say or prove that these forces acts along the line joining the centre of two charges. This force is directly proportional to magnitude of charges and inversly proportional to square of R

# VECTOR FORM OF COULOMB’S LAW:

Let consider two charges +Q1 and +Q2 and the distance from centre of first charge to the centre of second charge is R. As these charges are same so Q2 charge exert force on Q1 and Q1 charge exert force on Q2.

For direction we need unit vector

# LIMITATION OF COULOMB’S LAW:

It is valid only when both charges are at rest. It is not valid if both charges are in motion. It is also valid when one charge is moving mean in motion and other charge is at rest

*Originally published at **https://dooogly4u.blogspot.com** on June 2, 2020.*