Question

What is the importance of fuse in electrical circuits? Total load of a house is 2200 W. Electricity is supplied at 220 V. What should be the rating of fuse used in the house? Write down the commercial unit of electrical energy.

Hint:

When selecting a fuse, ensure the fuse rating is slightly higher than the normal operating current of the circuit to prevent unnecessary blows.

Answer 1

A fuse is an essential safety device used in electrical circuits. It prevents damage to the electrical appliances and wiring by melting and breaking the circuit when the current exceeds a safe value, thereby protecting the circuit from overheating and potential fires. The rating of the fuse is based on the maximum current that the circuit is expected to handle.
The current in the circuit can be calculated using the formula: \[ I = \frac{P}{V} = \frac{2200 \, \text{W}}{220 \, \text{V}} = 10 \, \text{A} \] Therefore, the fuse should have a rating of at least 10 A.
The commercial unit of electrical energy is the kWh (kilowatt-hour), which is the energy consumed by a 1 kW load in 1 hour. 1 kWh is equivalent to 1000 watts used for 1 hour.