All the heat generated in a 5 ohms resistor by 2A flowing for 30 seconds is used to evaporate 5g of a liquid at its boiling point. Which of the following is the correct value of the specific latent heat of the liquid?
-
A.
120J -
B.
60Jg-1 -
C.
120Jg-1 -
D.
1500J -
E.
1500Jg-1
Correct Answer: Option C
Explanation
Heat energy = Electrical energy
mL = I2RT
5 x L = 2 x 2 x 5 x 30
L = 120Jg-1