Compressors

11. Adiabatic compression is one in which

  1. temperature during compression remains constant
  2. no heat leaves or enters the compressor cylinder during cornpression
  3. temperature rise follows a linear relationship
  4. work done is maximum
  5. entropy decreases.

Correct answer: (B)
no heat leaves or enters the compressor cylinder during cornpression

12. Aeroplanes employ following type of compressor

  1. radial flow
  2. axial flow
  3. centrifugal
  4. combination of above
  5. none of the above.

Correct answer: (B)
axial flow

13. After-cooler is used to

  1. cool the air
  2. decrease the delivery temperature for ease in handling
  3. cause moisture and oil vapour to drop out
  4. reduce volume
  5. increase pressure.

Correct answer: (C)
cause moisture and oil vapour to drop out

14. Air-fuel ratio in a jet engine will be of the order of

  1. 10:01
  2. 15:01
  3. 20:01
  4. 60:01:00
  5. 100:01:00

Correct answer: (D)
60:01:00

15. An air compressor may be controlled by

  1. throttle control
  2. clearance control
  3. blow-off control
  4. any one of the above
  5. none of the above.

Correct answer: (D)
any one of the above

16. An air receiver is to be placed outside. Should it be placed in

  1. sun
  2. shade
  3. rain
  4. enclosed room
  5. anywhere.

Correct answer: (E)
anywhere.

17. An ideal air compressor cycle with clearance on p-v diagram can be represented by following processes

  1. one adiabatic, two isobaric, and one constant volume
  2. two adiabatic and two isobaric
  3. two adiabatic, one isobaric and one constant volume,
  4. one adiabatic, one isobaric and two constant volume
  5. two isobaric, two adiabatic and one constant volume.

Correct answer: (B)
two adiabatic and two isobaric

18. An ideal air compressor cycle without clearance on p-v diagram can be represented by following processes

  1. one adiabatic, two isobaric, and one constant volume
  2. two adiabatic and two isobaric
  3. two adiabatic, one isobaric and one constant volume
  4. one adiabatic, one isobaric and two constant volume
  5. two isobaric, two adiabatic and one constant volume.

Correct answer: (A)
one adiabatic, two isobaric, and one constant volume

19. As the turbine inlet temperature increases, the thermal efficiency of gas turbine for the optimum pressure ratio

  1. increases
  2. decreases
  3. remains same
  4. first increases and then decreases
  5. first decreases and then increases.

Correct answer: (A)
increases

20. As the value of index ‘«’ is decreased, the volumetric efficiency will

  1. increase
  2. decrease
  3. remain unaffected
  4. may increase/decrease depending on compressor clearance
  5. none of the above.

Correct answer: (B)
decrease

Previous
Page 2 of 19
Next
Copyright © EngineeringMCQ.com