Electricity & Megnetism

# Electrical Conductors and Insulators

Conductors and electrical insulators are opposite materials. Conductors are electrical particles that move easily, the opposite of what happens with insulators.

Conductors are electrical particles existing in a body capable of moving with great ease, as, for example, in metals and in the human body.

When this movement happens with great difficulty, or does not happen, we say that this body is an electrical insulator .

We have as an example screwdrivers, where the handle part is made of plastic and rubber, both electrical insulators. Electrified

conductors in electrostatic equilibrium Electrostatic equilibrium occurs when the electrified body reaches stability, that is, when it is not possible to have an orderly movement of electric charges. This definition was created from an experiment known as the Coulomb sphere.

: any body is placed inside a hollow sphere and it is noticed, through this, that the electric charges remain on the surface of the sphere, in search of stability, while the test piece does not become electrified when it touches the inner part of the sphere .

We see then that inside an electrified conductor, the electric field is zero, regardless of the shape of that body.

Such an experiment is known as electrostatic shielding , as it is able to protect bodies or the body inside them from the influences of external electrical charges.

Electric field and potential of spherical conductors of radius R

To determine the definition of the themes, it is assumed that the point charge Q, existing in both, is concentrated in the center of the sphere, and may be hollow or massive.

Electric field external to the sphere and electric potential of the conductor (inner or surface point)

Electrically isolated

system We have this system when bodies electrified together exchange charges with each other, but not outside the set.

Principle of Conservation of Electric Charge is the definition that in an electrically isolated system, the algebraic sum of the electric charges of all bodies is always constant.