Solved Problems Under Carnot Engines, Thermodynamics

1.     a mixture of fuel  and air at 37⁰C is taken by an internal combustion engine and the highest temperature after combustion is 520⁰C . calculate the carnot efficiency of an engine working between these two temperatures.

2.     a reversible engine convert  1/5^th of the heat input to do work, when the temperature of the sink is is reduced by 72⁰C , its efficiency is doubled . find the temperature of the source  and the sink

3.     how many grams of water at 0⁰C can a freezer with a performance coefficient  of  5 make into ice cubes at 0⁰C with work input of 3.6MJ. take latent heat of ice as 90cal/g.

4.     a refrigerator operate with its cold reservoir at -10⁰C and rejects eats to its surrounding at 32⁰C. if 300g of water are turned to ice at 0⁰C, calculate the total workdone  by the motor assuming  there is maximum theoretical efficiency ( L_f= 3.3× 10⁵ J/kg).

5.     a carnot engine whose high temperature reservoir is at 700k, takes 1000J of heat at this temperature in one cycle  and gives up 240J to the low temperature reservoir . calculate the low temperature reservoir and efficiency of the cycle.

ANSWERS TO THE ABOVE QUESTIONS