Water in an electric kettle connected to a 220 V supply takes 5 minutes to reach its boiling point. How long will it take if the supply voltage falls to 200 V ?

Explanation

To solve the problem, we need to determine how long it will take for water in an electric kettle to reach its boiling point when the supply voltage is reduced from 220 V to 200 V. We will use the relationship between power, voltage, and resistance, as well as the concept of heat energy.

### Step-by-Step Solution:

1. **Understand the Power Equation**:
The power \( P \) of the electric kettle can be expressed as:
\[
P = I \times V
...