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Switch:
 A switch is used to break or connect a circuit.
 When the switch is in ‘On position’ it completes the circuit and current flows through it.
 When the switch is in ‘Off position’ the circuit is broken and current stops flowing through
it.
 A switch is also called a key.
ELECTRICAL APPLIANCE:An electrical appliance is a device that uses electricity to

perform certain function by to transformation of electrical energy.
Eg. Electric Bulb
 In a glowing electric bulb the energy is transformed into heat and light energy.
 A bulb has a wire called the filament which glows when current flows through it.
 When this wire breaks, the bulb stops glowing and it is said to be fused.
Conducting wires:
 A metal conductor wire used to connect various devices in an electric circuit.
 All metals are good conductor of electricity.
Ex: Copper is used as conducting wires as it offers very little resistance on passing
electric current through it.

Ammeter : It is a device used to measure the amount of current flowing through a circuit. It
is denoted by A.

Voltmeter: It is a device used to measure the potential difference between two terminals of
a circuit. It is denoted by a symbol V.
Potential difference: Electric current flows from positive terminal to negative terminal. The
difference of potential of these two terminals is known as potential difference.