Question

When a fuse is rated 8A, it means :

• A. It will not work if current is less than 8A
• B. It has a resistance of 8 ohm
• C. It will work only if current is 8A
• D. It will burn if current exceeds 8A

Answer 1

The correct option is D It will burn if current exceeds 8A

The work of fuse wire to protect electric appliances if some particular amount of current that should not be passed through is passed accidentally.

The resistance of fuse wire is set as such if current exceeds from a particular amount heat is produced and and temperature of the fuse wire increases and it reaches to it's melting point and it melts and circuit becomes an open circuit.

So if a wire is rated 8 A, it means the resistance is set to such a value that if current is exceeded from 8 A value then fuse wire will melt down.