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Electricity

The Heating Effect of Current.

When we looked at ohm's law, it was mentioned
that an increase in current through
a component will increase its temperature.

The wires that connect the components of a circuit
also get hotter with increasing current. The more
current passing through the wire, the hotter it gets.
A very hot wire can melt or set fire to its insulation.

A fuse is made from a thin piece of wire that
is designed to melt when a current passes through
it that is higher than the fuse's rating.
In this way the fuse protects the rest of the circuit
from damage caused by too high a current.

To find the reason why current has a heating effect,
we must look at the resistance of the wire itself.

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