The Faraday cage leverages which property of a conductor?

The Faraday cage leverages which property of a conductor?

• A. They block all light from entering
• B. The interior electric field of a conductor is zero
• C. They store electrical charge indefinitely
• D. They resist heat transfer

Answer: (B)

The essential idea is that free charges in a conductor move in response to an external electric field until they cancel it inside. In a Faraday cage, external fields push charges to rearrange on the outer surface of the metal. The surface charges create their own electric field that opposed the outside field, so the net electric field inside the hollow region becomes essentially zero. That shielding effect is why a Faraday cage can protect anything inside from external electric influences in static or slowly varying conditions. The other options aren’t about this shielding mechanism (they relate to blocking light, storing charge indefinitely, or resisting heat), so they don’t explain how a conductor protects the interior.

The essential idea is that free charges in a conductor move in response to an external electric field until they cancel it inside. In a Faraday cage, external fields push charges to rearrange on the outer surface of the metal. The surface charges create their own electric field that opposed the outside field, so the net electric field inside the hollow region becomes essentially zero. That shielding effect is why a Faraday cage can protect anything inside from external electric influences in static or slowly varying conditions. The other options aren’t about this shielding mechanism (they relate to blocking light, storing charge indefinitely, or resisting heat), so they don’t explain how a conductor protects the interior.