Question

A reversible heat engine A(based on carnot cycle ) absorbs heat from a reservoir at 1000 K and rejects
heat to a reservoir at `T_(2)`. A second reversible engine B absorbs, the same amount of heat as rejected by
the engine A, from the reservoir at `T_(2)` and rejects energy to a reservoir at 360 K.
If the efficienices of engines A and B are the same then the temperature `T_(2)` is .
A. 680 K
B. 640 K
C. 600 K
D. none

Answer 1

Correct Answer - D
For heat engines A: `eta= (1000- T_(2))/(1000) rArreta_(B) = (T_(2) - 360)/(T_(2))`
`eta_(A) = eta_(B)`
`So(1000-T_(2))/(1000)=(T_(2) - 360)/(T_(2)) = T_(2) = sqrt(360 xx 1000)=600 K`