Question

Temperature variation with time is plotted for an object as shown in figure. The mass of the object is 200 g. Heat is supplied to the object at constant rate of 1 KW. Specific heat of object in liquid phase is –

• A. 3000 J/kg-K
• B. 1000 J/kg-K
• C. 4000 J/kg-K
• D. 2000 J/kg-K

Answer 1

Answer: (C)

4000 J/kg-K

Answer 2

H = $\frac{dQ}{dt}$ = mcdT/dt

$\frac{H}{mdT/dt}$ = C = $\frac{1 \times 10^{3}}{0.2 \times \frac{500}{400}}$ = $\frac{10^{4} \times 2}{5}$

C = 0.4 × 10⁴

C = 4000 $\frac{J}{KgK}$.