1 (a) Explain the method to determine air
consumption with the help of neat sketch. (6 Marks)

(b) Differentiate between brake power and
frictional power. (4 Marks)

(c) Write notes on mechanical efficiency
and volumetric efficiency. (6 Marks)

(d) A single cylinder petrol engine
working on two-stroke cycle develops indicated power of 5kW. If the mean
effective pressure is 7 bar and piston diameter is 100 mm, calculate the
average piston speed. (4 Marks)

2(a) What are the advantages and
disadvantages of excess air in combustion? (4 Marks)

(b)Explain complete and incomplete
combustion. (6 Marks)

(c) Write a note on enthalpy and internal
energy of combustion. (6 Marks)

(d) Determine the molal analysis of
products of combustion when octane C

_{8}H_{18 }is burned with 200% of air. (4 Marks)
3(a) Describe the air standard Otto cycle
and derive an expression for efficiency as a function of compression ratio. (8
Marks)

(b) Distinguish between air standard
cycle and actual cycle in general. What are the reasons for deviations? (8
Marks)

(c) A reversible engine converts
one-sixth of the heat input into work, when the temperature of sink is reduced
to 70

^{0}C, its efficiency is doubled. Find the temperature of source and sink. (4 Marks)
4(a) Obtain an expression for thermal
efficiency of dual cycle in terms of compression ratio, cut-off ratio and
pressure ratio. (8 Marks)

(b) Explain various methods of improving
the specific work output and thermal efficiency of gas turbine cycle. (8 Marks)

(c) A gas turbine set takes air at 27

^{0}C and 1 atm. The pressure is 4 and the maximum temperature is 560^{0}C. The compressor and turbine efficiencies are 0.83 and 0.85 respectively. Determine the overall efficiency if regenerator efficiency is 0.75. (4 Marks)
5(a) Discuss the effects of exhaust
pressure and superheating on Rankine cycle efficiency. (6 Marks)

(b) Draw an ideal regenerative vapour
power cycle on temperature entropy diagram. What are its advantages? How is the
cycle approximated in practice? (10 Marks)

(c) In a thermal power plant, the
saturated liquid water coming out of condenser is at 10 kPa. This liquid is to
be recycled by pumping into boiler which is maintained at 2.5 kPa. Determine
the work to be done (per kg of water) on the pump if isentropic efficiency of
the pump is 0.8. (4 Marks)

6(a) What is multistage compression?
Discuss the advantages. (6 Marks)

(b) Explain the need of multi-staging in
reciprocating compression. (6 Marks)

(c) Enumerate the applications of
compressed air. (4 Marks)

(d) A two stage air compressor receives
air at 3 m3/min at 1 bar and delivers it at 10 bar. Assuming perfect
intercooling, determine the power required. (4 Marks)

7(a) Write a note on essential properties
of a refrigerant material. (4 Marks)

(b) Differentiate between vapour
refrigeration system and air refrigeration system. (6 Marks)

(c) With neat sketch explain the working
of the steam jet refrigeration. (6 Marks)

(d) Determine the least power of a
perfect reversed heat engine that makes 400 kg of ice per hour at -8

^{0}C from feed water at 18^{0}C. Assuming specific heat of ice as 2.09 kJ/kg and latent heat 334 kJ/kg. (4 Marks)
8(a) Sketch and explain various
psychrometric processes on psychrometric chart. (6 Marks)

(b) Define the term bypass factor used
for cooling or heating coil and find expression for the same. (6 Marks)

(c) Define terms wet bulb temperature and
dew point temperature. (4 Marks)

(d)Moist air saturated at 1.7

^{0}C enters the heating coil at the rate of 600 m^{3}/min. Air leaves the coil at 37.8^{0}C. Find the required amount of heat addition per hour. (4 Marks)
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