An ideal refrigerator has a freezer at a temperature of `-13^(@)C`. The coefficient of performance of the engine is `5`. The temperature of the air (to which heat is rejected) will be

Options

A. `325^(@)C`
B. `325 K`
C. `39^(@)C`
D. `320^(@)C`

Answer

C

Explanation

Coefficient of performance
`K = (T_2)/(T_(1)-T_(2)) implies 5=((273-13))/(T_(1)-(273-13)) = (260)/(T_(1)-260)`
`= 5T_(1)-1300=260implies 5T_(1) = 1560`
`implies T_(1)=312K rarr 39^@C`.