A Carnot's engine is made to work between `200^(@)C` and `0^(@)C` first and then between `0^(@)C` and `-200^(@)C`. The ratio of efficiencies of the engine in the two cases is

Options

A. `1:15`
B. `1:1`
C. `1:2`
D. `1.73:1`

Answer

D

Explanation

Case-1: `T_(2) =^(@)C =273K`
`T_(1) =200^(@) C =473 K`
`eta_(1) =1- (273)/(473) `
Case-2: `T_(2), =0^(@)C =273C`
`T_(t)=0^(@)C 273K`
`eta_(1) =1- (73)/(273) =eta=(200)/(273)`
`((eta_(2))/(eta_(1))=(473)/(273)=(1.73)/(1))`