A Carnot engine, whose efficiency is `40%`, takes in heat from a source maintained at a temperature of 500K. It is desired to have an engine of efficiency `60%`. Then, the intake temperature for the same exhaust (sink) temperature must be:

Options

A. efficiency of carnot engine cannot be made larger than 50 %
B. 1200 K
C. 750 K
D. 600 K

Answer

C

Explanation

The efficiency of engine , `eta=1-(T_("sink"))/(T_("source"))`
`rArr" " 0.4=1-(T_("sink"))/(500)rArrT_("sink")=0.6xx500=300K`
` 0.6=1-(300K)/(T_("source"))rArrT_("source")=(300K)/(0.4)=750K`