# IT TAKES 4 MINUTES TO BOIL A QUANTITY OF WATER ELECTRICALLY. HOW LONG WILL IT TAKE TO BOIL SAME QUANTITY OF WATER USING THE SAME HEATING COIL BUT WITH THE CURRENT DOUBLED

- A. 64 minutes
- B. 32 minutes
- C. 8 minutes
- D. 2 minutes
**E. 1 minute ✓**

The answer to the question is: **E. 1 minute**

To calculate how long it will take to boil the same quantity of water using the same heating coil but with the current doubled, we can use the formula:

**Q = I² × R × t**

Where:

**Q = heat energy required to raise the temperature of the water**

**I = current **

**R = resistance of the heating coil**

**t = time**

Assuming that the resistance of the heating coil remains constant, we can use the equation:

**Q1 = I² × R × t1**

**Q2 = (2I)² × R × t2 (current doubled)**

Since the quantity of water and the heating coil are constant, we can equate Q1 and Q2

**I² × R × t1 = (2I)² × R × t2**

**I² × R × t1 = 4I² × R × t2**

**Solving for t2 = I² × R × t1 / 4I² × R**

**t2 = t1 / 4**

Given that, t1 = 4 minutes

**t2 = 4 minutes / 4 = 1 minute**

Therefore, if it takes 4 minutes to boil a quantity of water electrically with a certain current, it will take 1 minute to boil the same quantity of water using the same heating coil but with the current doubled.