# Conductors in the external electric field. Faraday’s law

This post is about Fardey’s Law and conductor’s behaviour and features in the external electric field.

Let’s consider a case when the neutral conductor is in the electric field of other charged objects. In this situation the conductor will experience a phenomena of electrical induction, or redistribution of charges in a conductor.

As a result there will be redistributed electrical charge on the surface, Figure 16. The charge will be distributed so that the part of the conductor close to positive charge of a field, will contain electrons. All the positive charges will be localised on the other part of the conductor. These charges are called induced charges.

1. If there are no charges under the conduction surface, then there are is electric field. It means that an external electric field does not penetrate inside the conductor. This feature is the basis of electric safety principle. Figure 16.
2. Total charge induced on the internal surface of the induced layer is equal to the total charge inside the conductor with the opposite sign. Figure 17. An electric field inside the conductor is 0. According to the Gauss theorem

$\int EdS=0$

then the total charge of the conductor is equal to 0.

$\sum {q}_{i}+{q}_{ind}=0$

Then

${q}_{ind}=–\sum {q}_{i}$

3. Induction charge on the external surface of the conductor is equal to the induced charge on the inner surface of a conductor. Figure 18.

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