A refrigerator works between $4^{\mathrm{o }}\mathrm{C}$ and ${30}^{\mathrm{o}}\mathrm{C}$. It is required to remove $\text{600}$ calories of heat every second in order to keep the temperature of the refrigerated space constant. The power required is:

(Take $\text{1}$ cal = $\text{4}\text{.2}$ Joules)

• A

  $\mathrm{2.365 }\text{W}$
• B

  $23.65\text{W}$
• Correct answer
  C

  $236.5\text{W}$
• D

  $2365\text{W}$

Solution

$\frac{Q_2}{Q_1}=\frac{T_2}{T_1}\Rightarrow \frac{600+\mathrm{w}}{600}=\frac{303}{277}=\frac{277+26}{277}$

$1+\frac{\mathrm{w}}{600}=1+\frac{26}{277}$

$\mathrm{w}=600\times \frac{26}{277}\times 4.2$

$\mathrm{w}=236.5$

Hence, the correct answer is option: 'C'.