1) Describe the working of four stroke petrol engine.

2) Describe the various stages of combustion in SI engines.

3) Sketch B.H.P Vs mech efficiency curves for single cylinder, 4-storke CI and SI engines when both are developing the same power at same speed. Comment on the curves.

4) describe the heat balance sheet with the help of neat sketches.

5) Steam enters a nozzle passing a mass flow of 14kg/s at the pressure of 3MN/m2 and temperature of 300oC. After expansion to an exit pressure of 0.5 MN/m2, the exit velocity was 800m/s. Find:

a) The nozzle efficiency

b) If the losses only in the divergent portion,

Compute the velocity of steam at the throat.

6) Discuss the working of a rotary compressor with neat sketch.

7) prepare a brief note on “AIR LIQUEFACTION SYSTEM”.

8) A vapour compression refrigeration plant works between the pressure limits of 5.3 bar and 2.1 bar. The vapour is superheated at the end of compression, its temperature being 37oC. The vapour is superheated by 5oC before entering the compressor. If the specific heat of superheated vapour is 0.63kJ/kg K, compute the co-efficient of performance of the plant. Use the data given below.

Pressure          saturationoC                liquid                       latent heat(kJ/kg)
Bar                        temp                     heat(kJ/kg)

5.3                         15.5                       56.15                       144.9
2.1                        -14.0                       25.12                       158.7

9) describe the details that are needed to arrive at the cooling load in summer air conditioning applications?

10) Describe the working of the summer air conditioning system.