Hydraulic Machines

11. Any change in load is adjusted by adjusting following parameter on turbine

  1. net head
  2. absolute velocity
  3. blade velocity
  4. flow
  5. relative velocity of flow at inlet.

Correct answer: (D)
flow

12. Axial flow pump is started with its delivery valve

  1. kept fully closed
  2. kept fully open
  3. irrespective of any position
  4. kept 50% open
  5. none of the above.

Correct answer: (B)
kept fully open

13. Casting of a centrifugal pump is designed so as to minimize

  1. friction loss
  2. cavitation
  3. static head
  4. loss of kinetic energy
  5. starting time.

Correct answer: (D)
loss of kinetic energy

14. Centrifugal pump is started with its delivery valve

  1. kept fully closed
  2. kept fully open
  3. irrespective of any position
  4. kept 50% open
  5. none of the above.

Correct answer: (A)
kept fully closed

15. For small discharge at high pressure, following pump is preferred

  1. centrifugal
  2. axial flow
  3. mixed flow
  4. propeller
  5. reciprocating.

Correct answer: (E)
reciprocating.

16. For starting an axial flow pump, its delivery valve should be

  1. closed
  2. open
  3. depends on starting condition and flow desired
  4. could be either open or closed
  5. partly open and partly closed.

Correct answer: (B)
open

17. For very high discharge at low pressure such as for flood control and irrigation applications, following type of pump is preferred

  1. centrifugal
  2. axial flow
  3. reciprocating
  4. mixed flow
  5. none of the above.

Correct answer: (B)
axial flow

18. Francis turbine is best suited for

  1. medium head application from 24 to 180 m
  2. low head installation up to 30 m
  3. high head installation above 180 m
  4. all types of heads
  5. none of the above.

Correct answer: (A)
medium head application from 24 to 180 m

19. Francis, Kaplan and propeller turbines fall under the category of

  1. Impulse turbines
  2. Reaction turbines
  3. Axial flow turbines
  4. Mixed flow turbines
  5. Reaction-cum-impulse turbines.

Correct answer: (B)
Reaction turbines

20. Guide angle as per the aerofoil theory of Kaplan turbine blade design is defined as the angle between

  1. lift and resultant force
  2. drag and resultant force
  3. lift and tangential force
  4. lift and drag
  5. resultant force and tangential force.

Correct answer: (A)
lift and resultant force

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