An electric kettle consumes `1 kW` of electric power when operated at `220 V`. A fuse-wire of what rating must be used for it ?

Options

A. `1 A`
B. `2 A`
C. `4 A`
D. `5 A`

Explanation

To determine the appropriate fuse wire rating for the electric kettle that consumes 1 kW of power at 220 V, we can follow these steps:

### Step-by-Step Solution:

1. **Convert Power to SI Units**:
The power of the kettle is given as 1 kW. We convert this to watts:
\[ P = 1 \text{ kW} = 1000 \text{ W} \]

2. **Identify the Operating Voltage**:
The operating voltage of the kettle is given as:
\[ V = 220 \text{ V} \]

3. **Use the Power Formula to Find Current**:
We know the relationship between power (P), voltage (V), and current (I) is given by the formula:
\[ P = V \times I \]
Rearranging this formula to find the current (I):
\[ I = \frac{P}{V} \]

4. **Substitute the Values**:
Now, we can substitute the values of P and V into the formula:
\[ I = \frac{1000 \text{ W}}{220 \text{ V}} \approx 4.545 \text{ A} \]

5. **Determine the Fuse Rating**:
The calculated current is approximately 4.545 A. Since fuse wires are rated in whole numbers, we need to choose a fuse that can handle at least this current. The next standard fuse rating above 4.545 A is 5 A.

6. **Conclusion**:
Therefore, the appropriate fuse wire rating to be used for the kettle is:
\[ \text{Fuse Rating} = 5 \text{ A} \]

### Summary:
The fuse wire rating that must be used for the electric kettle consuming 1 kW at 220 V is **5 A**.