Faraday Cages

A Faraday Cage is a a cage or an enclosure made of conductive material.   The Faraday cage is used to protect a device or a region from external electric fields.  The Faraday cage is named after Sir Michael Faraday who invented them in 1836.

Faraday proved that no electric field can exist inside a room made of conductive material. 

The Faraday cage can block static and non-static electric field.  The charge passes through the conductive surface of the cage.

When an airplane or a car is struck by lightning, it acts as a Faraday's cage protecting the passengers from the lightning. 

Faraday cage are used in laboratories to protect sensitive instruments. 


Electric conductors used in instrumentation are protected from external interference by the use of a Shield.  The shield serves to protect the conductors from electromagnetic couplings.