Hydraulic Turbines and Jets MCQ

1. Which component is not provided to Pelton wheel turbine?

  1. Jet
  2. Penstock
  3. Draft tube
  4. Casing
Answer
Answer. c

2. If the turbine has kinetic energy and pressure energy of water at its inlet, then such turbine is known as

  1. impulse turbine
  2. reaction turbine
  3. pelton wheel turbine
  4. low head turbine
Answer
Answer. b

3. To generate 1000 hp under a head of 81 m while working at a speed of 500 rpm, the turbine of choice would be

  1. Kaplan
  2. Pelton
  3. Francis
  4. Bulb
Answer
Answer. c

4. Performance characteristic curves indicate that unit discharge is independent of unit speed for

  1. Pelton wheel
  2. Low specific speed Francis turbine
  3. High specific speed Francis turbine
  4. Kaplan turbine
Answer
Answer. a

5. Kaplan turbine is used for

  1. medium heads
  2. low heads
  3. very high heads
  4. high heads
Answer
Answer. b

6. A small hydro project is designed to have a head of 35 m at the entry point of turbine. Which of the following turbines should be mostly selected for efficient operation?

  1. Pelton
  2. Turg0
  3. Kaplan
  4. Francis
Answer
Answer. c

7. What is a turbo machine that extracts energy from a liquid by virtue of rotating blade system called?

  1. Rotameter
  2. Turbine
  3. Viscometer
  4. Pump
Answer
Answer. b

8. A Pelton turbine is

  1. a reaction turbine
  2. both a pressure and reaction turbine
  3. a velocity turbine
  4. a pressure turbine
Answer
Answer. c

9. The turbine to be used for 450 m head of water is

  1. Pelton wheel
  2. Francis turbine
  3. Kaplan turbine
  4. None of these
Answer
Answer. a

10. In a Kaplan turbine runner, the number of blades are generally

  1. 4 to 8
  2. 2 to 4
  3. 16 to 24
  4. 8 to 6
Answer
Answer. a

11. In a reaction turbine, the draft tube is used

  1. to run the turbine full
  2. to prevent air to enter the turbine
  3. to transport water to downstream
  4. to increase the effective head of water
Answer
Answer. d

12. In impulse turbine the total energy at inlet is

  1. pressure energy and kinetic energy
  2. pressure energy
  3. kinetic energy
  4. mechanical energy
Answer
Answer. c

13. Which hydraulic turbine more efficient at part load operation?

  1. Francis turbine
  2. Pelton wheel
  3. Kaplan turbine
  4. Propeller turbine
Answer
Answer. c

14. Draft tube for a reaction turbine is arranged for

  1. Safety purpose only
  2. Increasing velocity head
  3. Converting kinetic head into pressure head
  4. Diverting water only
Answer
Answer. c

15. The speed ratio for Pelton wheel varies from

  1. 0.45 to 0.50
  2. 0.6 to 0.7
  3. 0.3 to 0.4
  4. 0.8 to 0.9
Answer
Answer. a

16. Consider the specific speed ranges of the following turbines

  1. Francis
  2. Kaplan
  3. Pelton

The increasing order of specific speed is

  1. 3, 1, 2
  2. 2, 3, 1
  3. 1, 2, 3
  4. 3, 2, 1
Answer
Answer. a

17. The unit power of the reaction turbine

  1. Increases with the unit speed
  2. Decreases with the unit speed
  3. Decreases and increases with the unit speed
  4. Increases and decreases with the unit speed
Answer
Answer. c

18. A Nozzle device is used to convert the

  1. total energy to pressure
  2. total energy to velocity
  3. kinetic energy to mechanical energy
  4. potential energy to kinetic energy
Answer
Answer. b

19. Euler equation of water turbine is derived on the basis of

  1. conservation of mass
  2. rate of change of linear momentum
  3. rate of change of angular momentum
  4. rate of change of velocity
Answer
Answer. c

20. The hydraulic efficiency of an impulse turbine is maximum when the velocity of wheel is _________ that of the jet velocity.

  1. one-fourth
  2. one-half
  3. three-fourth
  4. double
Answer
Answer. b