Operating an electrical switch is like turning on a water faucet. Behind the faucet (or switch) there is a source of water (or electricity), a way to transport it, and pressure to make it flow. The faucet's water source is a reservoir or pumping station. A pump provides enough pressure for the water to travel through the pipes.
The switch's electrical source is a power generating station â€“ a dam, or a coal or natural gas power plant. A generator provides the pressure for the electrical current to travel or flow through electrical conductors or wires.
Three factors determine the resistance of a substance to the flow of electricity:
â€¢ What it is made of.
â€¢ Its size.
â€¢ Its temperature.
Substances with very little resistance to the flow of electrical current are called conductors. Examples are metals.
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