Heat is supplied uniformly at the rate of 100W to 1.0 x 10¯²kg of a liquid for 20 seconds. If the temperature of the liquid rises by 5°C; then the specific heat capacity of the liquid is

A. 2.0 x 10²Jkg⁻¹K⁻¹
B. 2.0 x 10²Jkg⁻¹
C. 4.0 x 10⁴Jkg⁻¹K⁻¹
D. 4.0 x 10⁴Jkg⁻¹

Correct Answer:

Option C = 4.0 x 10⁴Jkg⁻¹K⁻¹

Explanation

Heat energy = Electrical Energy

MCθ = power x time

5 x 1 x 10⁻² x C = 100 x 20

C = ²⁰⁰/₅×10²

= 4 x 10⁴ Jkg⁻¹K⁻¹