What is Electrostatic Shielding?

What is Electrostatic Shielding?

Electrostatic shielding is the process of isolating a certain region of space from the external field. It is based on the fact that the electric field inside a conductor is zero. Electrostatic shielding is the best way to protect some area in a vacuum from the influence of the external electric field.


Electrostatic shielding is the incident that is observed when a Faraday cage operates to block the effects of an electric field. It is the occurrence when a charged or uncharged conductor has a cavity and no charge is present in cavity, and then there will be no net charge anywhere on the surface of cavity (inner surface). Such a cage can block the effects of an exterior field on its internal contents, or the effects of an internal field on the exterior environment. So, it is the phenomenon of defensive a definite area of space from the outer electric field.

  • The electric field inside a conductor is zero. The electric field inside the cavity and inside the substance of conductor = zero. But the electric field on the outer surface is not zero.
  • Electric Potential is constant throughout conductor and potential on outer surface = potential on inner surface = potential inside material of the conductor.
  • There is no net charge anywhere on the internal surface. No electrostatic potential is constant throughout the volume of the conductor and has the same values as on its surface.

Real-life example –

During a thunder accompanied by lightning, it is safer to sit inside a bus than in open ground or under a tree. The metal body of the bus provides electrostatic shielding, where the electric field is zero.

During the lightning thunderstorm, it is advised to stay inside the car and not under trees or in the open ground because the outer metallic body of the car acts as an electromagnetic shield from the lightning.

During lightning, the electric discharge passes through the body of the bus.

Application: Microwave ovens surround energy within itself, shielding the outside from harmful radiation.

In a coaxial cable, the middle conductor is protected by electrostatic shield by connecting the outer conductor to the ground.