Refrigerator A works between `-10^@C` and `27^@C`, while refrigerator B works between `-27^@C` and `17^@C`, both removing heat equal to 2000J from the freezer. Which of the two is the better refrigerator?

Explanation

In case of refrigerator A,
`T_(1)= 27+273= 300K`,
`T_(2)= -10+273= 263K`
`beta= (T_(2))/(T_(1)-T_(2))= (263)/(300-263)=(263)/(37)= 7.1`
In case of refrigerator B,
`T_(1)=17+273= 290K`,
`beta=(T_(2))/(T_(1)-T_(2))= (246)/(290-246)=(246)/(44)= 5.6`
Hence, refrigerator A is better than refrigerator B.