AP EAPCET 20-Aug-2021 Shift 2 Paper

Given, sink temperature, T2=27°C=300K
Case I Efficiency, η1=40%
Case II Efficiency, η2=60%
Let temperature of source in two cases be T1 and T′1.
As we know that,
η1=1−

T2

T1

⇒

40

100

=1−

300

T1

⇒T1=500K
and η2=1−

T2

T′1

60

100

=1−

300

T′1

⇒

300

T′1

=

40

100

⇒T′1=750K
∴ Change is temperature, ΔT=T′1−T1 =750−500=250K