Compressors

1. 1 m of air at atmospheric condition weighs approximately

1. 0.5 kg
2. 1.0 kg
3. 1.3 kg
4. 2.2 kg
5. 3.2 kg.

View answer

2. A centrifugal compressor works on the principle of

1. conversion of pressure energy into kinetic energy
2. conversion of kinetic energy into pres¬sure energy
3. centripetal action
4. generating pressure directly
5. combination of (a) and (d).

View answer

3. A closed gas turbine in which fuel is burnt directly in the air is not possible because of

1. high pressure ratio
2. increasing gas temperature
3. high specific volume
4. high friction losses
5. paucity of 02.

View answer

4. A compressor at high altitude will draw

1. more power
2. less power
3. same power
4. more/less power depending on other factors
5. none of the above.

View answer

5. A gas turbine used in air craft should have

1. high h.p. and low weight
2. low weight and small frontal area
3. small frontal area and high h.p.
4. high speed and high h.p.
5. all of the above.

View answer

6. A jet engine works on the principle of conservation of

1. mass
2. energy
3. flow
4. linear momentum
5. angular momentum.

View answer

7. A rocket engine for the combustion of its fuel

1. carries its own oxygen
2. uses surrounding air
3. uses compressed atmospheric air
4. does not require oxygen
5. depends on electrical energy supplied by solar cells.

View answer

8. A rocket works with maximum overall efficiency when air craft velocity is equal to the

1. jet velocity
2. twice the jet velocity
3. half the jet velocity
4. average of the jet velocity
5. no such co-relationship with jet velocity exists.

View answer

9. A simple turbo-jet engine is basically

1. a propeller system
2. gas-turbine engine equipped with a propulsive nozzle and diffuse*
3. chemical rocket regine
4. ram-jet enigne
5. none of the above.

View answer

10. Actual compression curve is

1. same as isothermal
2. same as adiabatic
3. better than isothermal and adiabatic
4. in between isothermal and adiabatic
5. none of the above.

View answer