Heat and Thermodynamics

Problems

1. Calculate the efficiency of Carnot's engine working between 100 °C and 0 °C.

    

   Ans. 26.8%

2. A Carnot's engine is operated in the reverse direction as a refrigerator between 300 K and 450 K. If it receives 1000 calories of heat from the reservoir at 300 K, what is the amount of heat delivered at 450 K.

    

   Ans.1500 calories

3. A Carnot's engine has a low temperature reservoir at 7 °C with efficiency of 40%. It is desired to increase the efficiency to 50%. By how many degrees should the temperature of the high temperature reservoir be increased?

    

   Ans. 93.3 °C

4. An engine works in a Carnot's cycle between 27 °C and 127 °C and the work output per cycle is 300 kgm-meters. Calculate the heat supplied to the engine from the source.

    

   Ans. 2803 calories ...