Water of mass 1.5kg is heated from from 30oC to 80oC using an electric kettle which is rated 5A, 230V. Calculate the time taken to reach the final destination [specific heat capacity of water 4200Jkg-1K-1]
-
4.57 minutes
- 5.02 minutes
- 7.30 minutes
- 10.04 minutes
The correct answer is: A
Explanation
t = \(\frac{MC\theta}{2} = \frac{1.5 \times 4200 \times 50}{5 \times 230}\)= 273.91s or 4.57 mins