Question

Explain the process of corona discharge.

Answer 1

• When a spherical conductor of radius r carries a charge q, the surface charge density is given by,

          `sigma=q/(4pir^2)`

• For a pointed end, r is very small, therefore σ is very large. The particles of air coming in contact with pointed ends gets charged and repelled.
• In this way an electric wind is set up which takes away the charge continuously from the pointed ends of conductor.
• This process of spraying the charge is called corona discharge.