Question

(i) Explain the importance of using fuse in a household electric circuit.

Hint:

Always replace blown fuses with the correct rating to maintain the protection level. Never use a higher-rated fuse as it might not protect the circuit effectively.

Answer 1

The fuse is an essential safety device used in electrical circuits to prevent damage to appliances and wiring. It consists of a thin wire that melts when the current passing through it exceeds a predetermined limit. The primary importance of a fuse in a household electric circuit is: 1. Protection from Overload: Fuses are designed to protect electrical circuits from excessive current flow. When too much current flows due to an overload (like too many appliances being plugged in), the fuse wire melts, breaking the circuit and preventing further damage. Without a fuse, the excessive current could cause the wires to overheat, possibly leading to a fire. 2. Prevention of Appliance Damage: Household appliances are designed to operate within specific current ranges. A fuse helps prevent appliances from damage due to surges of electricity. If a surge or short circuit occurs, the fuse blows, cutting off the power supply and saving the appliance from overheating or burning out. 3. Fire Safety: By melting when the current exceeds safe limits, fuses help avoid fire hazards. Overloaded electrical circuits, if left unchecked, could lead to overheating of wires and could start a fire. A fuse acts as an automatic shut-off mechanism. 4. Economic Benefit: While fuses need to be replaced after they blow, they are cost-effective compared to the potential damage that could be caused by electrical fires or the destruction of expensive appliances. In essence, fuses are vital for electrical safety, ensuring that any sudden increase in current is quickly addressed, preventing hazards, and maintaining the integrity of the household electrical system.