Final answer:
A 5A fuse should be used for an electric kettle that consumes 1 kW of electric power at 220 V, as the current drawn would be just over 4.545 A, and fuses should have a higher rating than the actual current for safety headroom.
Step-by-step explanation:
An electric kettle consumes 1 kW of electric power when operated at 220 V.
To determine the fuse wire rating required for the electric kettle, we use the formula Power (P) = Voltage (V) × Current (I).
We rearrange the formula to find the current as I = P / V. Plugging in the values gives us I = 1000 W / 220 V = 4.545 A.
Considering that fuses are rated in whole numbers and we require some safety headroom, we should use a fuse that exceeds this current value slightly.
Therefore, a 5A fuse would be appropriate.
In context, electrical appliances are rated in amperes for safe operation, and so are the fuses. It is crucial to select the correct ampere rating for a fuse to prevent overloading, which could otherwise lead to electrical fires or damage to the appliance.