The efficiency of a Carnot's engine at a particular source and sink temperature is `(1)/(2)` .When the sink temperature is reduced by `100^(@)C`, the engine efficiency, becomes `(2)/(3)`. Find the source temperature.

Explanation

efficiency, `eta = 1 - T_2/T_1`
Where, `T_2` = sink temperature
`T_1`= source temperature
`1 - T_2/T_1" . . . . (i)"`
`1-((T_2 -100)/T_1)" . . . . (ii)"`
From eqn. (i), `T_2/T_1 = 1/2` and eqn. (ii) `(T_2)/(T_2 -100) = 3/2 rArr T_2 = 300 K`
Substituting in eqn. (i) `T_1 = 600 K`