# Limit on Faraday's cage (rearranging charges)

• olu
In summary, the conversation discusses the concept of Faraday's cage and how applying a magnetic field can cause the charges in the cage to rearrange, resulting in a net field of zero inside the cage. However, there is a question about whether it is possible to apply a strong enough field to cancel out all the charges and still have a non-zero net field inside the cage. The conversation also suggests providing specific numbers and orders of magnitude to better understand the situation.
olu
Having a question regarding Faraday's cage,Applying a magnetic field over the cage, will cause the charges in the conducting cage to rearrange, thus causing another field which opposes the first field. This will give a net field inside the cage of zero (this is why we are safe in a car during a lightning).

However, since we have a finite amount of charges in the conductive cage. Is it possible to apply a field strong enough so that all the charges have rearranged to oppose the field, but with the fact that all the charges is not enough charges to cancel the field, and thus giving a net field inside the cage which is not zero?
Oscar

olu said:
we have a finite amount of charges in the conductive cage.

Could you put a number on that? It could help you to get a handle on what you are saying. What field strengths are you considering? If this isn't a fruitless 'irresistible force and immovable object' type question then you need to supply some orders of magnitude for the causes and effects that you are discussing.

## What is a Faraday's cage?

A Faraday's cage is a metallic enclosure that is designed to block external electric fields. It works by redistributing the charges on its surface, cancelling out the electric field inside the cage.

## What is the limit on rearranging charges in a Faraday's cage?

The limit on rearranging charges in a Faraday's cage is that the electric field inside the cage cannot be reduced to zero. This is due to the fact that charges can only be redistributed, not created or destroyed.

## How is the limit on rearranging charges related to the size of the cage?

The limit on rearranging charges is directly related to the size of the Faraday's cage. As the size of the cage increases, the amount of charges that can be redistributed also increases, allowing for a stronger cancellation of the electric field.

## Can the limit on rearranging charges be exceeded?

No, the limit on rearranging charges in a Faraday's cage cannot be exceeded. It is a fundamental law of physics that charges cannot be created or destroyed, only redistributed. Therefore, the electric field inside the cage can never be completely eliminated.

## What factors can affect the effectiveness of a Faraday's cage in blocking electric fields?

The effectiveness of a Faraday's cage in blocking electric fields can be affected by factors such as the thickness and conductivity of the metal used, the size of the cage, and the strength of the external electric field. Additionally, any gaps or openings in the cage can also reduce its effectiveness.

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