Water boils in an electric kettle in `15 min` after being switched on . Using the same main supply , should the length of the heating element be increased or decreased if the water is to be boiled in `10 min`? Why ?

Explanation

To solve the problem of whether the length of the heating element in an electric kettle should be increased or decreased to boil water in 10 minutes instead of 15 minutes, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Relationship Between Power and Time**:
- The power (P) required to boil water is inversely proportional to the time (t) taken to boil it. This means that if we want to reduce the time, we need to increase the power.

2. **Use the Power Formula**:
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