JEE MainPhysicsThermal Properties of Matter
A solid substance of mass 2 kg is heated uniformly by a constant power source of 500 W . The temperature-time heating curve of the substance shows a solid heating phase, a melting plateau, and a liquid heating phase. During the liquid heating phase, the temperature of the substance increases from 80^ C to 110^ C in the time interval from t = 7 min to t = 8 min . The specific heat capacity of the substance in its liqu
Correct answer
500
Step-by-step solution
The time taken for the liquid phase to heat up is: t = 8 min - 7 min = 1 min = 60 s Total heat supplied during this phase: Q = P t = 500 60 = 30000 J The change in temperature is: T = 110^ C - 80^ C = 30^ C Using the sensible heat formula Q = mc T : 30000 = 2 c 30 30000 = 60c c = 30000 60 = 500 J kg ⁻¹ ^ C ⁻¹ Answer: 500