Top 50+ Solved Air Compressors MCQ Questions Answer
Q. An ideal air compressor cycle with clearance on p-v diagram can be represented by following processes
a. one adiabatic, two isobaric, and one constant volume
b. two adiabatic and two isobaric
c. two adiabatic, one isobaric and one constant volume,
d. one adiabatic, one isobaric and two constant volume
Q. The work done per unit mass of air in compression will be least when n is equal to
a. 1
b. 1.2
c. 1.3
d. 1.4
Q. Isothermal compression though most efficient, but is not -practicable because
a. it requires very big cylinder
b. it does not increase pressure much
c. it is impossible in practice
d. compressor has to run at very slow speed to achieve it
Q. Ratio of indicated H.P. and brake H.P. is known as
a. mechanical efficiency
b. volumetric efficiency
c. isothermal efficiency
d. adiabatic efficiency
Q. The ratio of work doen per cycle to the swept volume in case of compressor is called
a. compression index
b. compression ratio
c. compressor efficiency
d. mean effective pressure
Q. Cylinder clearance in a compressor should be
a. as large as possible
b. as small as possible
c. about 50% of swept volume
d. about 100% of swept volume
Q. Ratio of compression is the ratio of
a. gauge discharge pressure to the gauge intake pressure
b. absolute discharge pressure to the absolute intake pressure
c. pressures at discharge and suction corresponding to same temperature
d. stroke volume and clearance volume
Q. Clearance volume in actual reciprocating compressors is essential
a. to accommodate Valves in the cylinder head
b. to provide cushioning effect
c. to attain high volumetric efficiency
d. to provide cushioning effect and also to avoid mechanical bang of piston with cylinder hea
Q. The net work input required for compressor with increase in clearance volume
a. increases
b. decreases
c. remains same
d. increases/decreases depending on compressor capacity
Q. Ratio of indicated h.p. to shaft h.p. is known as
a. compressor efficiency
b. isothermal efficiency
c. volumetric efficiency
d. mechanical efficiency
Q. Volumetric efficiency is
a. the ratio of stroke volume to clearance volume
b. the ratio of the air actually delivered to the amount of piston displacement
c. reciprocal of compression ratio
d. index of compressor performance
Q. Volumetric efficiency of a compressor with clearance volume
a. increases with increase in compression ratio
b. decreases with increase in compression ratio
c. is not dependent upon compression ratio
d. may increase/decrease depending on compressor capacity
Q. Volumetric efficiency of a compressor without clearance volume
a. increases with increase in compression ratio
b. decreases with increase in compression ratio
c. is not dependent upon compression ratio
d. may increase/decrease depending on compressor capacity
Q. The clearance volume of the air compressor is kept minimum because
a. it allows maximum compression to be achieved
b. it greatly affects volumetric efficiency
c. it results in minimum work
d. it permits isothermal compression
Q. Which is false statement about multistage compression.
a. Power consumption per unit of air delivered is low
b. Volumetric efficiency is high
c. It is best suited for compression ratios around 7:1
d. The moisture in air is condensed in the intercooler