Question

State the characteristics required in a material to be used as an effective fuse wire.

Answer 1

Hint:
A fuse is a safety element used to safeguard our appliances from very high currents which can damage the electronic equipment. This and the working of a fuse element will give us the solution.

Step by step solution:
A fuse element is installed as a safety precaution to protect our electronic equipment from any damage due to high currents flowing in the circuit.

Usually a regular fuse element attached to our switch boards consists of an LED indicator indicating the state of the current flow and thin strip of wire, which completes the circuit for electricity to pass through it. This thin wire strip is known as the fuse wire.

As long the fuse wire stays intact the current will flow in the circuit shown by the glowing LED. But whenever, due to high current passing through the circuit, the fuse wire breaks (usually known as - blown fuse), the LED will stop glowing. The fuse wire would need to be replaced for the electricity flow to resume.

From these things, we can comfortably say that the fuse wire’s material needs to have the following properties:

1.)Low resistance, to allow the current to flow without much ohmic losses.
2.)It should have a low melting point. This is necessary, so that as soon as a high current passes through the wire, enough heat energy is released for the wire to melt.

Note:
Even though, low melting point is necessary for the fuse wire, it's necessary to remember that a fuse wire shouldn’t heat up easily for normal operating current range.
The fuse wire should only break when a high current that could have damaged the electrical appliances had passed through it, and not due to continuous heating up under operating current condition. This is important to remember.