Hydropower Engineering MCQ

1. A certain hydropower plant utilizes the flow as it occurs, without any provision for storage. It is premised that a defined minimum dry weather flow is available. Such a plant is classified as

  1. Diverted-flow plant
  2. Pooled storage plant
  3. Base-load plant
  4. Run-off-river plant
Answer. d

2. A hydraulic press has a ram of 300 mm diameter and a plunger of 45 mm diameter. When the force applied at the plunger is 50 N, the weight lifted by the hydraulic press will be nearly

  1. 2133 N
  2. 2223 N
  3. 2316 N
  4. 2406 N
Answer. b

3. Weber number can be best connected to which of the following:

  1. Formation of liquid droplet
  2. High-speed flow of a gas
  3. Flow in closed conduits
  4. Sloping interface between fluids of different densities
Answer. a

4. The gases are considered incompressible when Mach number is

  1. equal to 1.0
  2. equal to 0.5
  3. less than 0.2
  4. more than 0.3
Answer. c

5. The meta centric height of a floating body

  1. is the distance between the meta centre of buoyancy
  2. is the distance between the meta centre and centre of gravity
  3. does not control the stability of a floating body
  4. is the same about longitudinal and transverse axis
Answer. b

6. A vertical triangular gate has one side in a free surface, with vertex downwards. If the height of the gate is ‘h’, the depth of centre of pressure is

  1. h/3
  2. h/4
  3. h/2
  4. 2h/3
Answer. c

7. If the load on a hydro power plant varies from a minimum of 12000 kW to peak to 42000 kW for a certain period, the load factor would be

  1. 35.72%
  2. 50%
  3. 100%
  4. 64.25%
Answer. b

8. Surge tanks are provided

  1. For storage of water
  2. To increase the velocity of flow in a pipeline
  3. As overflow controllers
  4. To guard against water hammer
Answer. d

9. The sum of suction head and delivery head is known as

  1. Static head
  2. Delivery head
  3. Suction head
  4. Manometric head
Answer. a

10. Consider the following statements:

  1. Surge tanks are not substitutes for forebays.
  2. Pumped storage power plants are a boon to power generation.
  3. Water hammer in penstocks is not dangerous.
  4. Kaplan turbines are used in low head power plants.

Which of the above statements are correct?

  1. ii and iv only
  2. i and iv only
  3. ii and iii only
  4. i and iii only
Answer. a

11. Two turbo-generators, each of capacity 25,000 kW, have been installed at a hydel power station. The load on the hydel plant varies from 15,000 kW to 40,000 kW. The total installed plant capacity and the load factor are nearly

  1. 40,000 kW and 68.8%
  2. 50,000 kW and 68.8%
  3. 40,000 kW and 62.3%
  4. 50,000 kW and 62.3%
Answer. b

12. The purpose of surge tank is

  1. To control the pressure variations due to rapid changes in the pipe line flow
  2. To eliminate water hammer possibilities
  3. To regulate flow of water to turbines by providing necessary regarding head of water
  4. All of the above
Answer. d

13. If V1 and V2 are the velocities of water at inlet and outlet of the draft tube respectively, then the efficiency of a draft tube is

  1. (V1 – V2)/(V1)
  2. (V21 – V22)/(V21)
  3. (V21)/(V21 – V22)
  4. (V1)/(V1 – V2)
Answer. b

14. The absolute pressure head at the inlet to the pump minus the vapour pressure head (in absolute units) plus the velocity head is known as

  1. Maximum suction lift
  2. Net positive suction head
  3. Manometric head
  4. Cavitation
Answer. b

15. Kinematic similarity between model and prototype means

  1. similarity of forces
  2. similarity of shape
  3. similarity of motion
  4. similarity of discharge
Answer. c

16. Type of Jump occurs for Froude number Fr = 4.5 to 9.0

  1. Steady
  2. Strong
  3. Weak
  4. Oscillating
Answer. a

17. The main function of surge tanks that are connected to the penstocks in the power house is to

  1. provide a free water surface near the turóins
  2. protect penstocks from bursting
  3. acts as a reservoir
  4. provide protection against water hammer
Answer. d

18. The length of the hydraulic jump is found to be

  1. 10 to 15 times depth of jump
  2. 1 to 2 times depth of jump
  3. 5 to 7 times depth of jump
  4. has no relation to the depth of jump
Answer. c

19. Rotameter is a device used for measuring

  1. discharge through pipes
  2. discharge through open channel
  3. discharge through notch
  4. discharge through weir
Answer. a

20. If the peak load on a power plant having a capacity of 100 MW is 70 MW during a given week (7-days), and the energy produced is 5880000 kWh, the capacity factor (in %) for the plant for the said week is

  1. 35
  2. 50
  3. 65
  4. 30
Answer. a