Question

1. Calculate the efficiency of a steam engine working at a temperature 573 K assuming the temperature of the surrounding as 298 K.

2. How much useful work can be done by carnot engine working between 0°C and 100°C if the heat supplied is 1900kJ.

3. Calculate the amount of heat supplied to a carnot cycle working between 368K and 288K if maximum obtain is 895J.

Answer 1

 e_max = (T_steam- T_air)/T_steam = $\frac{573-298}{573}=0.48$ or 48%

efficiency of carnot engine = \$1-\frac{T_L}{T_H}=1-\frac{273}{373}=0.27$

useful work = heat $\times$ efficiency = 1900$\times$0.27=513 J