The efficiency of a Carnot engine is 50% and temperature of sink is 500 K. If temperature of source is kept constant and its efficiency raised to 60%, then the required temp. of sink will be:

Options

A. 100 K
B. 600 K
C. 400 K
D. 500 K

Answer

C

Explanation

`eta=1-(T_(2))/(T_(1)) rArr (50)/(100)=1-(500)/(T_(1)) rArr T_(1)=1000 K`
`eta_(2)=1-(T_(2).)/(T_(1)) rArr (60)/(100) =1-(T_(2).)/(1000) rArr T_(2).=400 K`
`therefore` Correct choice is (c ).