Question

a carnot engine absorbs heat from a reservoir at the temperature 127°c, if the engine absorbs 1000 calories of heat from the high temperature reservoir, find the work done and the efficiency

Answer 1

Hello Dear.

Question is little bit incomplete.If the Engine is absorbing the Heat, then there mus be some rejection of the heat. If there is no Rejection then the work done will be 1000 calories and efficiency will be 100%, which cannot be possible in actual case.
So, rejection of Heat must be taking place.
Let us assuming the Rejection of Heat is 400 Calories.

Now, Solving the Question.

Heat Absorbs = 1000 Calories.
Heat Rejects = 400 Calories.

Work Done = Heat Absorbs - Heat Rejects
 = 1000 - 400
 = 600 calories.

Now,
Efficiency = (Work Done/Heat Absorbs) × 100%
 = (600/1000) × 100%
 = 60%

∴ Efficiency of the Engine is 60 %. 


Hope it helps.