Practice Test: Question Set - 14
1. Pick up the wrong statement
- (A) Large gas turbines
employ axial flow compressors
- (B) Axial flow
compressors are more stable than centrifugal type compressors but not as
efficient
- (C) Axial flow
compressors have high capacity and efficiency
- (D) Axial flow
compressors have instability region of operation
2. The power available for takeoff and climb in case of turbojet engine as compared to reciprocating engine is
- (A) Less
- (B) More
- (C) Same
- (D) May be less or more
depending on ambient conditions
3. A closed gas turbine in which fuel is burnt directly in the air is not possible because of
- (A) Paucity of O2
- (B) Increasing gas temperature
- (C) High specific volume
- (D) High friction losses
4. Choose the correct statement
- (A) Gas turbine requires
lot of cooling water
- (B) Gas turbine is
capable of rapid start up and loading
- (C) Gas turbines has flat efficiency at part
loads
- (D) Gas turbines have
high standby losses and require lot of maintenance
5. In the cross compounding of the gas turbine plant
- (A) H.P. compressor is
connected to H.P. turbine and L.P. compressor to L.P. turbine
- (B) H.P. compressor is
connected to L.P. turbine and L.P. compressor is connected to H.P. turbine
- (C) Both the arrangements
can be employed
- (D) All are connected in series
6. A jet engine works on the principle of conservation of
- (A) Mass
- (B) Energy
- (C) Flow
- (D) Linear momentum
7. Which of the following fuels can be used in turbojet engines?
- (A) Liquid hydrogen
- (B) High speed diesel oil
- (C) Kerosene
- (D) Methyl alcohol
8. Propulsive efficiency is defined as ratio of
- (A) Thrust power and fuel energy
- (B) Engine output and propulsive power
- (C) Propulsive power and fuel input
- (D) Thrust power and propulsive power
9. In jet engines, paraffin is usually used as the fuel because of its
- (A) High calorific value
- (B) Ease of atomisation
- (C) Low freezing point
- (D) Both (A) and (C) above
10. A rocket engine for the combustion of its fuel
- (A) Carries its own oxygen
- (B) Uses surrounding air
- (C) Uses compressed atmospheric air
- (D) Does not require oxygen
11. A rocket works with maximum overall efficiency when air craft velocity is equal to the
- (A) Jet velocity
- (B) Twice the jet velocity
- (C) Half the jet velocity
- (D) Average of the jet velocity
12. Propulsion efficiency of the following order is obtained in practice
- (A) 34%
- (B) 50%
- (C) 60%
- (D) 72%
13. In jet engines the products of combustion after passing through the gas turbine are discharged into
- (A) Atmosphere
- (B) Back to the compressor
- (C) Discharge nozzle
- (D) Vacuum
14. The air entry velocity m a rocket as compared to aircraft is
- (A) Same
- (B) More
- (C) Less
- (D) Zero
15. The weight per horse power ratio for gas in Turbine as compared to I.C. engine and steam turbine is
- (A) Same
- (B) Higher
- (C) Lower
- (D) None of these
Blogger Comment
Facebook Comment