Question

what is an electric discharge? under what condition does it occur?

Answer 1

Electric discharge refers to the flow of electricity or electric charge through a medium. The medium may be a solid, a liquid or a gas. When two points of different electrical potential make contact in the medium in which they are placed, it causes an electric discharge.

There are many types of electric discharge such as brush discharge, electric arc, electrostatic discharge, vacuum arc and partial discharge.

Answer 2

The electric discharge is actually about the flow of electron or may be called the electric charge flowing through a medium. The differential electrical potential causes the electric discharge in the medium . So when there is build up of electron  in a material happen the electric discharge developed .The surplus electron causes the development of negative charges . These electrons flows in order to find the  positive charges causes the electric discharge.

Hope this helps.