Question

14. For which combination of working temperature the efficiency of carnot engine is highest?
a) 60k, 40k b) 40k, 20 K c) 80K, 60k d) 100k, 80k
​

Answer 1

Efficiency of Carnot's engine η=1−

T

H

T

L

(A) : η

A

=1−

40

20

=0.5

(B) : η

B

=1−

60

40

=0.33

(C) : η

C

=1−

100

80

=0.2

(D) : η

D

=1−

80

60

=0.25

Thus the Carnot's engine, working on the combination given in option C, has the least efficiency.