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A refrigerator works between 4^(@)C and ...

A refrigerator works between `4^(@)C and 30^(@)C`. It is required to remove 600 cal of heat every second in order to keep the temperature of the refrigerator space constant. The power required is (take 1 cal = 4.2 J)

A

23.65 W

B

236.5 W

C

2365 W

D

2.365 W

Text Solution

Verified by Experts

The correct Answer is:
B
Coefficient of performance of the refrigerator,
`e = (T_2)/(T_(1) - T_(2)) = (277)/(303 - 277) = (277)/(26)`
Here, `T_(2) = 273 + 4 = 277 K, T_(1) = 273 + 30 = 303 K`
Also, `e = (Q_2)/(W)` [ where, `Q_(2)` = heat absorbed by the refrigerator from colder body W = work done by refrigerator]
or, `W = (Q_2)/e = 600 xx 4.2 xx 26/277 = 236.53 J`
As work done by the refrigerator is 236.53 J per second, then power required is 236.53 W.
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