1.

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 refrigerator space constant.The power required is (Take `1calorie= 4.2 J`)A. `23.65W`B. `236.5W`C. `2365W`D. `2.365W`

Answer» Correct Answer - B
Here,`T_(2)= 4^(@)C= 4+273= 277K`
`T_(1)= 30^(@)C=30+273= 303K`
`Q_(2)= 600cal//s= 600xx4.2J//s`
`P=?`
As `COP=(Q_(2))/W= (T_(2))/(T_(1)-T_(2))`
`:. W=(Q_(2)(T_(1)_T_(2)))/(T_(2))= (600xx4.2(303-277))/(277)`
`W= 236.5 J//s= 236.5 "Watt"`.


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