Faraday cage

Definition

A Faraday cage is an enclosure made of conductive material that blocks external static and non-static electric fields by channeling electricity along and around the exterior. This effect is used to protect sensitive electronic equipment from electromagnetic interference.

5 Must Know Facts For Your Next Test

1. Faraday cages work because the conductive material redistributes electric charges, cancelling out external electric fields within the enclosure.
2. The effectiveness of a Faraday cage depends on factors such as the conductivity, thickness of the material, and size of any gaps in the structure.
3. Faraday cages can block not only static electric fields but also time-varying electromagnetic waves like radio waves.
4. They are commonly used in applications requiring shielding from electromagnetic interference (EMI), such as in laboratories and electronic equipment enclosures.
5. Michael Faraday, after whom the cage is named, demonstrated this principle in 1836.

Review Questions

• How does a Faraday cage redistribute electric charges to block external electric fields?
• What factors influence the effectiveness of a Faraday cage?
• Give an example of a practical application for a Faraday cage.

Related terms

Electromagnetic Interference (EMI): Disturbance generated by an external source that affects an electrical circuit through electromagnetic induction or radiation.

Electric Field:

A region around a charged particle where other charged particles experience a force.

Conductor:

A material that allows the flow of electrical current due to its low resistance.