Q. An electric immersion heater of $1.08\ kW$ is immersed in water. After the water has reached a temperature of $100℃$, how much time will be required to produce $100\ g$ of steam
A) $210\ s$
B) $105\ s$
C) $420\ s$
D) $50\ s$
Explanation
(a) The heat required for producing $1g$ of steam $= 540\ cal$
$= 540 \times 4.2\ J = 2268\ J$
Energy given by immersion heater is
$= 1.08\ kW = 1080W$
Now time taken to produce $100g$ of steam
$= \frac{2268 \times 100}{1080} = 210\ sec$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.