The boiling point of water at a pressure of 50 atm is 538 K.Compare the theoretical efficiencies of a stem engine operating between the boiling point of water at
50 atm pressure , assuming the temperature of the sink to be `35^(@)C` in each case.

Explanation

Boiling point of water at 50 atm pressure `(T_b)=265^@C`
=265+273=538 K
(i)Boiling point of water at 1 atm pressure `(T_b)=100^@C`
=100+273=373 K
% Efficiency of steam engine `=[(T_1-T_2)/T_1]xx100`
`=[(538-373)/538]xx100`
=0.3066 x 100 = 30.66%
(ii) Boiling point of water at 50 atm pressure `(T_b)=35^@C`
=35+273 =328 K
% Efficiency of steam engine =`[(T_1-T_2)/T_1]xx100`
`=[(538-328)/538]xx100=(210xx100)/538`
=39.03 %