Question

A fuse is a safety device used for the purpose of protecting a circuit against ________
1. Under current
2. Leakage current
3. Excess current
4. Under voltage

Answer 1

Correct Answer - Option 3 : Excess current

Fuse:

• Fuse is a safety device used for the protection of electrical equipment against excessive current.
• It is always connected in series with the circuit.
• In the event of excess current, the fuse element melts and opens up the circuit.

 

Properties of a fuse element:

• The material used for fuse elements must be of a low melting point.
• It should have a low ohmic loss(low i2R loss).
• It should have high conductivity (or low resistivity).
• It should be of low cost.
• It should not be affected by oxidation(fuse element should not react with oxygen to form metal oxides) i.e. free from deterioration.