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A refrigerator works between 4^@C and 30...

A refrigerator works between `4^@C` and `30^@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 _____ (1 cal = 4.2 Joules)

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
`T_1`=4+273=277 K
`T_2`=30+273=303 K
`Q_1`=-600 cal
`rArr` For refrigerator `Q_1/Q_2=T_1/T_2`
`therefore (Q_2+W)/Q_2=T_1/T_2 [ because Q_1=Q_2+W]`
`therefore 1+W/Q_2=277/303`
`therefore W=(277/303-1)Q_2`
`=-26/303xx(-600xx4.2)`
`=(26xx600xx4.2)/303`
=216.2 W
`approx` 236.5 W, closest value.
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