6. A normal shock-

A. causes disruption and reversal of flow pattern

B. may occur only in a diverging passage

C. is more service than an oblique shock

D. moves with a velocity equal to the sonic velocity

Click for Answer/Explanation

Correct Answer is A

7. Employing superheated steam in turbines leads to-

A. Increase in the erosion of blading

B. A decrease in the erosion of blading

C. No erosion in blading

D. No change in the erosion of blading

Click for Answer/Explanation

Correct Answer is B

8. In a reaction turbine stage enthalpy drop in the stator blades is 4.62 Kj/Kg and that in the rotor blades is 2.38 Kj/Kg. The degree of reaction of the stage is-

A. 0.55

B. 0.43

C. 0.34

D. 0.29

Click for Answer/Explanation

Correct Answer is C

Using the Formula-

Degree of reaction = [(Δh)rotor] / [( Δh)rotor + (Δh)stator]

9. An emergency of a steam turbine trips the turbine when-

  1. shafts exceed 100 % of its rated speed
  2. condenser becomes hot due to inadequate cooling water circulation
  3. lubrication system fails
  4. balancing of the turbine is not proper

A. 1, 2 & 3

B. 2 & 4

C. 2, 3 & 4

D. All the above

Click for Answer/Explanation

Correct Answer is C

10. The absolute jet exit velocity from a jet engine is 2800 m/s and the forward flight velocity is 1400 m/s. Find the propulsive efficiency is-

A. 55.52%

B. 66.67%

C. 75.25%

D. 80%

Click for Answer/Explanation

Correct Answer is B

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