Compressors
91. Ratio of compression is the ratio of
- gauge discharge pressure to the gauge intake pressure
- absolute discharge pressure to the ab-solute intake pressure
- pressures at discharge and suction cor-responding to same temperature
- stroke volume and clearance volume
- none of the above.
Correct answer: (B)
absolute discharge pressure to the ab-solute intake pressure
92. Ratio of indicated H.P. and brake H.P. is known as
- mechanical efficiency
- volumetric efficiency
- isothermal efficiency
- adiabatic efficiency
- relative efficiency.
Correct answer: (A)
mechanical efficiency
93. Ratio of indicated h.p. to shaft h.p. in known as
- compressor efficiency
- isothermal efficiency
- volumetric efficiency
- mechanical efficiency
- adiabatic efficiency.
Correct answer: (D)
mechanical efficiency
94. Reciprocating air compressor is best suited for
- large quantity of air at high pressure
- small quantity of air at high pressure
- small quantity of air at low pressure
- large quantity of air at low pressure
- any one of the above.
Correct answer: (A)
large quantity of air at high pressure
95. Reheating in gas turbine results in
- increase of work ratio
- decrease of thermal efficiency
- decrease of work ratio
- both (a) and (b) above
- both (b) and (c) above.
Correct answer: (D)
both (a) and (b) above
96. Reheating in multistage expansion gas turbine results in
- high thermal efficiency
- reduction in compressor work
- decrease of heat loss in exhaust
- maximum work output
- none of the above.
Correct answer: (D)
maximum work output
97. Rotary compressor is best suited for
- large quantity of air at high pressure
- small quantity of air at high pressure
- small quantity of air at low pressure
- large quantity of air at low pressure
- any one of the above.
Correct answer: (B)
small quantity of air at high pressure
98. Rotary compressors are suitable for
- large discharge at high pressure
- low discharge at high pressure
- large discharge at low pressure
- low discharge at low pressure
- there is no such limitation.
Correct answer: (C)
large discharge at low pressure
99. Separators in compressor installations are located
- before intercooler
- after intercooler
- after receiver
- between after-cooler and air receiver
- before suction.
Correct answer: (D)
between after-cooler and air receiver
100. Stalling of blades in axial flow compressor is the phenomenon of
- air stream blocking the passage
- motion of air at sonic velocity
- unsteady periodic and reversed flow
- air stream not able to follow the blade contour
- production of no air pressure.
Correct answer: (D)
air stream not able to follow the blade contour