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.