Electrostatic Shielding

Table of Contents

What is electrostatic shielding?

Electrostatic shielding is a phenomenon seen when a Faraday cage is used to block the effects of an electric field. The effects of external fields on the internal contents are blocked using the cage.

Electrostatic shielding applications

  • During a 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.
  • In a coaxial cable, the central conductor is protected by an electrostatic shield by connecting the outer conductor to the ground.

What is Faraday cage?

The Faraday cage is an enclosure that blocks the external electric fields in conductive materials. It is also known as the Faraday shield.

Michael Faraday, in the year 1800 invented Faraday’s cage. He found that when the metal cage, which acts as an electrical conductor, was charged, the charges appeared only on the surface with no effect on the interiors. When this was conducted on a large scale, he lined a room in a metal foil, allowing high-voltage discharges from an electrostatic generator. He used a device to detect the electric charges called an electroscope to prove his hypothesis that the outer surface of the metal foil was conducted by the current. In contrast, the interior of the room was devoid of electric charges.

How does Faraday cage work?

Faraday cage has a cage-like appearance made of fine metal mesh and chain-like fences, which vary in size and design. The cage can hold the electrostatic charges and electromagnetic fields such that they get distributed throughout the exterior of the material it is used on. The distribution of charges on the exterior surface happens so that the charges cancel with the charges in the interior.

Faraday cage applications

  • MRI scanning rooms: The rooms are built so that they prevent mixing the external radio frequency signals with the data from the MRI machine.
  • Microwave ovens: The mechanism used is based on the Faraday cage such that the electromagnetic energy within the oven is contained and the exterior is a shield from radiation.
  • They find application in analytical chemistry to reduce noise while making sensitive measurements.

Related Physics Articles:

Magnetic Field And Magnetic Field Lines
Maxwell’s Equations
Electromagnetic Waves

Frequently Asked Questions – FAQs


What is meant electromagnetic induction mean?

Electromagnetic or magnetic induction produces an electromotive force across an electrical conductor in a changing magnetic field.

Who discovered electromagnetic induction?

Physicist Michael Faraday discovered electromagnetic induction.

What is electrostatic shielding?

Electrostatic shielding is a phenomenon that is observed when a Faraday cage is employed to block electric field effects. The external field effects on the internal components are obstructed using the cage.

What is a Faraday cage?

The Faraday cage is an enclosed structure that is employed to block the external electric fields in conductive materials. This cage is also called the Faraday shield.

What are the main applications of the Faraday cage?

Faraday cages are used in MRI scanning rooms, microwave ovens, and other analytical chemistry applications.

Stay tuned with BYJU’S to learn more about other Physics related concepts.

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