Circuits

What we are going to learn today:

• What is a circuit?
• The basic components of a circuit
  And...
• The Switch

What is a circuit?

A circuit is a closed loop that electrons can travel in. A source of electricity, such as a battery, provides electrical energy in the circuit. ... The appliance may, for example, provide light or heat or mechanical energy.The flow of charges through a circuit is called electric current. The SI unit of electric current is ampere and donated by A. The direction of the electric current is conventionally from the positive terminal to the negative terminal of a cell.

• If any part of a circuit is broken, electric current does not flow through it and such a circuit is called an open circuit.
• If there are no breaks in a circuit, it provides a closed for the flow of electric current and such a circuit is called a closed circuit.
• Electric current can flow only through closed circuit.

Basic Components of a circuit

Every circuit is comprised of three major components:

• A conductive path, such as wire.
• A source of electricity, such as a battery or household wall outlet.
  And,
• A load that needs electrical power to operate, such as a lamp.

The Switch

A switch is a device that can break an electrical circuit by diverting the current from one conductor to another conductor or an insulator. These set of contacts are termed as open and closed. Open circuit means that the contacts are separated and the circuit is broken, so no current is flowing.

Whereas closed circuit means that the contacts are touching, the circuit is complete and the current is flowing. Switches are of many types and are used depending upon the device we are using. Generally, we use them in our house for controlling the fans, bulbs, call bells, power switches for devices like refrigerators, washing machines, etc.