Thermodynamics - Result Question 38
40. A refrigerator works between $4^{\circ} C$ and $30^{\circ} C$. It is required to remove 600 calories of heat every second in order to keep the temperature of the refrigerated space constant. The power required is:
(Take $1 cal=4.2$ joules)
[2016]
(a) $2.365 W$
(b) $23.65 W$
(c) $236.5 W$
(d) $2365 W$
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Answer:
Correct Answer: 40. (c)
Solution:
- (c) Given: $T_2=4^{\circ} C=4+273=277 K$
$T_1=30^{\circ} C=30+273=303 K$
$\beta=\frac{Q_2}{W}=\frac{T_2}{T_1-T_2}$
$\therefore \quad \beta=\frac{600 \times 4.2}{W}=\frac{277}{303-277}$
$\Rightarrow W=236.5$ joule Power $P=\frac{W}{t}=\frac{236.5 \text{ joule }}{1 sec}=236.5$ watt.
