Compressors, Gas Turbines & Jet Engines Mcqs - Set 3

1)   Mining industry usually employs following motive power___________________?

a. A.C. electric motor
b. compressed air
c. petrol engine
d. diesel engine
e. D.C. electric motor
Answer  Explanation 

ANSWER: compressed air

Explanation:
No explanation is available for this question!


2)   Separators in compressor installations are located_____________________?

a. before intercooler
b. after intercooler
c. after receiver
d. between after-cooler and air receiver
e. before suction
Answer  Explanation 

ANSWER: between after-cooler and air receiver

Explanation:
No explanation is available for this question!


3)   An air compressor may be controlled by____________________?

a. throttle control B. clearance control
b. blow-off control
c. any one of the above
d. none of the above
Answer  Explanation 

ANSWER: any one of the above

Explanation:
No explanation is available for this question!


4)   During peak load periods, the best method of controlling compressors is___________________?

a. start-stop motor
b. constant speed unloader
c. relief valve
d. variable speed
e. none of the above
Answer  Explanation 

ANSWER: constant speed unloader

Explanation:
No explanation is available for this question!


5)   The compressor performance at higher altitude compared to sea level will be _______________?

a. same
b. higher
c. lower
d. dependent on other factors
e. none of the above
Answer  Explanation 

ANSWER: lower

Explanation:
No explanation is available for this question!


6)   A centrifugal compressor works on the principle of__________________?

a. conversion of pressure energy into kinetic energy
b. conversion of kinetic energy into pres¬sure energy
c. centripetal action
d. generating pressure directly
e. combination of A. and D.
Answer  Explanation 

ANSWER: conversion of kinetic energy into pres¬sure energy

Explanation:
No explanation is available for this question!


7)   A compressor at high altitude will draw________________?

a. more power
b. less power
c. same power
d. more/less power depending on other factors
e. none of the above
Answer  Explanation 

ANSWER: less power

Explanation:
No explanation is available for this question!


8)   The thrust on the rotor in a centrifugal compressor is produced by________________?

a. radial component
b. axial component
c. tangential component
d. resultant component
Answer  Explanation 

ANSWER: axial component

Explanation:
No explanation is available for this question!


9)   The area of actual indicator diagram on an air compressor as compared to area of ideal indicator diagram is_____________________?

a. less
b. more
c. same
d. more/less depending on compressor capacity
e. unpredictable
Answer  Explanation 

ANSWER: more

Explanation:
No explanation is available for this question!


10)   To aviod moisture troubles, the compressed air main line should __________________?

a. rise gradually towards the point of use
b. drop gradually towards the point of use
c. be laid vertically
d. be laid exactly horizontally
e. none of the above
Answer  Explanation 

ANSWER: drop gradually towards the point of use

Explanation:
No explanation is available for this question!


11)   To avoid moisture troubles, the branch connections from compressed air lines should be taken from_________________?

a. top side of main
b. bottom side of main
c. left side of main
d. right side of main
e. any location
Answer  Explanation 

ANSWER: top side of main

Explanation:
No explanation is available for this question!


12)   For a compressor, least work will be done if the compression is________________ ?

a. isentropic
b. isothermal
c. polytropic
d. somewhere in between isentropic and isothermal
e. none of the above
Answer  Explanation 

ANSWER: isothermal

Explanation:
No explanation is available for this question!


13)   The compressor efficiecny is the__________________?

a. isothermal H.P/indicated H.R
b. isothermal H.P./shaft H.R
c. total output/air input
d. compression work/motor input
e. none Of the above
Answer  Explanation 

ANSWER: isothermal H.P/indicated H.R

Explanation:
No explanation is available for this question!


14)   For slow-speed large capacity compressor, following type of valve will be best suited________________?

a. poppet valve
b. mechanical valve of the corliss, sleeve, rotary or semirotary type
c. disc or feather type
d. any of the above
e. none of the above
Answer  Explanation 

ANSWER: disc or feather type

Explanation:
No explanation is available for this question!


15)   The volumetirc efficiency of a compressor is calculated on the basis of __________________?

a. volume of air inhaled at working conditions
b. volume of air inhaled at N.T.P. conditions
c. volume at 0°C and 1 kg/cm2
d. volume at 20°C and 1 kg/cm2
e. none of the above
Answer  Explanation 

ANSWER: volume of air inhaled at N.T.P. conditions

Explanation:
No explanation is available for this question!


16)   During base load operation, the best method of controlling compressor is ___________________?

a. start-stop motor
b. constant speed unloader
c. relief valve
d. variable speed
e. none of the above
Answer  Explanation 

ANSWER: start-stop motor

Explanation:
No explanation is available for this question!


17)   The volumetric efficiency of a compressor falls roughly as follows for every 100 m increase in elevation___________________?

a. 0.1%
b. 0.5%
c. 1.0%
d. 5%
e. 10%.
Answer  Explanation 

ANSWER: 1.0%

Explanation:
No explanation is available for this question!


18)   In a compressor, free air delivered is the actual volume delivered at the stated pressure reduced to ____________________?

a. N.T.P. conditions
b. intake temperature and pressure conditions
c. 0°C and 1 kg/cm2
d. 20°C and 1 kg/cm2
e. none of the above
Answer  Explanation 

ANSWER: intake temperature and pressure conditions

Explanation:
No explanation is available for this question!


19)   The advantage of multistage compression over single stage compression is ________________?

a. lower power consumption per unit of air delivered
b. higher volumetric efficiency
c. decreased discharge temperature
d. moisture free air
e. all of the above
Answer  Explanation 

ANSWER: all of the above

Explanation:
No explanation is available for this question!


20)   As the value of index ‘«’ is decreased, the volumetric efficiency will___________________?

a. increase
b. decrease
c. remain unaffected
d. may increase/decrease depending on compressor clearance
e. none of the above
Answer  Explanation 

ANSWER: decrease

Explanation:
No explanation is available for this question!