A Carnot engine, having an efficiency of `eta=1//10` as heat engine, is used as a refrigerator. If the work done on the system is 10J, the amount of energy absorbed from the reservoir at lower temperature is

Options

A. 99J
B. 90J
C. 1J
D. 100J

Answer

B

Explanation

`eta=(W)/(Q_1) implies (1)/(10)=(10)/(Q_1) implies Q_1 =100J`
Amount of energy absorbed from the reservoir at lower temperature (`Q_2)`
`Q_2 = Q_1 - W= 100-10=90 J`.