Electric circuits: elements and representation

An electric circuit is a route around which electrons circulate.

It consists of a generator, a cable, a switch and a receiver.

Electric current is the flow of electrons around a circuit

We need a generator in to maintain a current.

There are three types of materials.Conductors,Insulators,semiconductors:

Conductors

Conductors allow electric current to pass through them. All metals are conductors

Insulators

Insulators don’t allow an electric current to pass through them wood glass, plastic and the air are insulators

Semiconductors

Semiconductors have properties which are intermediate in magnitude between conductors and insulators. The most important examples are silicon and germanium.

The electric resistance of the material is the measure of the degree to which the material opposes an electric current flowing through it

Metals have hardly any electrical resistance whereas insulators have a very high level of resistance

Its value depends on the material used and its form.

Resistance increases with the length of the cable and decreases with its thickness

Elements of a circuit

The generator provides the necessary energy for electrons to circulate

The control elements direct and interrupt electric current

The receivers transform electric energy into usable energy

The protection elements protect circuits and people against potential problems