Question

Under what condition efficiency of carnot engine be 100% ?

Answer 1

Efficiency of a Carnot engine is given by

where, ${ T }{ 2 }$ = temperature of sink and
and ${ T }{ 1 }$ = temperature of sink source.
So n = 1 or 100%, ${ T }_{ 2 }$ = 0 K or heat is rejected into a sink at 0 K temperature.

Answer 2

When the input in Carnot engine is equal to the output