Top 150+ Solved Thermal Engineering 1 MCQ Questions Answer
Q. The actual vaccum in a condenser is equal to......
a. Barometric pressure + actual pressure
b. Barometric pressure - actual pressure
c. Gauge pressure + atmospheric pressure
d. Gauge pressure - atmospheric pressure
Q. According to Dalton’s law, the total pressure of the mixture of gases is equal to
a. greater of the partial pressures of all
b. average of the partial pressures of all
c. sum of the partial pressures of all
d. sum of the partial pressures of all divided by average molecular weight
Q. At ideal condition of vapour power cycle, reversible constant pressure heat rejection is carried out at
a. boiler
b. turbine
c. condenser
d. feed pump
Q. A condenser condenses the steam coming out from___________.
a. Boiler
b. Turbine
c. Economiser
d. Super heater
Q. What is use of the air pumps in the condenser?
a. Remove water
b. Air leaking in the condenser and to maintain the vacuum.
c. Maintain atmospheric pressure and the condenser.
d. Both (a) & (b).
Q. What is the correct formula for net work done of reciprocating engine?
a. Wnet = mean effective pressure × clearance volume
b. Wnet = mean effective pressure × total volume of cylinder
c. Wnet = mean effective pressure × displacement volume
d. none of the above
Q. Minimum work in compressor is possible when the value of adiabatic index n is equal to
a. 0.75
b. 1
c. 1.27
d. 1.35
Q. Compressed air coming out from a punctured football
a. becomes hotter
b. becomes cooler
c. remains at the same temperature
d. may become hotter or cooler depending upon the humidity of the surrounding air
Q. The capacity of a compressor is 5 m /min. 5 m /min refers to
a. standard air
b. free air
c. compressed air
d. compressed air at delivery pressure
Q. The overall isothermal efficiency of compressor is defined as the ratio of
a. isothermal h.p. to the BHP of motor
b. isothermal h.p. to adiabatic h.p.
c. power to drive compressor to isothermal h.p.
d. work to compress air isothermally to work for actual compression
Q. The- most efficient method of compressing air is to compress it
a. isothermally
b. adiabatically
c. isentropically
d. isochronically
Q. Maximum work is done in compressing air when the compression is
a. isothermal
b. adiabatic
c. polytropic
d. any one of the above
Q. The pressure and temperature conditions of air at the suction of compressor are
a. pressure sightly less than atmospheric and temperature slightly more than atmospheric.
b. slightly more than atmospheric
c. slightly less than atmospheric
d. pressure slightly more than atmospheric and temperature slightly less than atmospheric
Q. Isothermal compression effeicency can be attained by running the compressor
a. at very high speed
b. at very slow speed
c. at average speed
d. at zero speed
Q. The compressor capacity with decrease in suction temperature
a. increases
b. decreases
c. remains unaffected
d. may increase or decrease depending on compressor capacity