Q.1

Which of the following statement is correct ?

  • In an impulse turbine, the water impinges on the buckets with pressure energy.
  • In a reaction turbine, the water glides over the moving vanes with kinetic energy.
  • In an impulse turbine, the pressure of the flowing water remains unchanged and is equal to atmospheric pressure.
  • In a reaction turbine, the pressure of the flowing water increases after gliding over the vanes.
Q.2

The function of guide vanes in a reaction turbine is to

  • allow the water to enter the runner without shock
  • allow the water to flow over them, without forming eddies
  • allow the required quantity of water to enter the turbine
  • all of the above
Q.3

A reciprocating pump is also called a __________ displacement pump.

  • positive
  • negative
Q.4

Which of the following pump is sucessfully used for lifting water to the boilers?

  • Centrifugal pump
  • Reciprocating pump
  • Jet pump
  • Air-lift pump
Q.5

Power required to drive a centrifugal pump is __________ proportional to N3.

  • directly
  • inversely
Q.6

In an inward flow reaction turbine

  • the water flows parallel to the axis of the wheel
  • the water enters at the centre of the wheel and then flows towards the outer periphery of the wheel
  • the water enters the wheel at the outer periphery and then flows towards the centre of the wheel
  • the flow of water is partly radial and partly axial
Q.7

Manometric head is the actual head of water against which a centrifugal pump has to work.

  • Correct
  • Incorrect
Q.8

The head available at the inlet of the turbine is known as net or effective head.

  • Correct
  • Incorrect
Q.9

The efficiency of a reaction turbine for a given head __________ with the increase in speed.

  • decreases
  • increases
Q.10

If the ratio of corresponding velocities at corresponding points are equal, then the model and the prototype are said to have dynamic similarity.

  • Correct
  • Incorrect
Q.11

The jet ratio is defined as the ratio of the

  • diameter of jet to the diameter of Pelton wheel
  • velocity of jet to the velocity of Pelton wheel
  • diameter of Pelton wheel to the diameter of jet
  • velocity of Pelton wheel to the velocity of jet
Q.12

The working of which of the following hydraulic units is based on Pascal's law?

  • Air lift pump
  • Jet pump
  • Hydraulic coupling
  • Hydraulic press
Q.13

The hydraulic efficiency of an impulse turbine is the

  • ratio of the actual power produced by the turbine to the energy actually supplied by the turbine
  • ratio of the actual work available at the turbine to the energy imparted to the wheel
  • ratio of the work done on the wheel to the energy of the jet
  • none of the above
Q.14

In an axial flow reaction turbine, the water flows __________ to the axis of the wheel.

  • parallel
  • perpendicular
Q.15

The undershot water wheels are those in which

  • the wheel runs entirely by the weight of water
  • the wheel runs entirely by the impulse of water
  • the wheel runs partly by the weight of water and partly by the impulse of water
  • none of the above
Q.16

The cavitation in a hydraulic machine is mainly due to

  • low velocity
  • high velocity
  • low pressure
  • high pressure
Q.17

In an impulse turbine, the pressure of water both at entering and leaving the vanes, is atmospheric.

  • Agree
  • Disagree
Q.18

In an outward flow reaction turbine

  • the water flows parallel to the axis of the wheel
  • the water enters at the centre of the wheel and then flows towards the outer periphery of the wheel
  • the water enters the wheel at the outer periphery and then flows towards the centre of the wheel
  • the flow of water is partly radial and partly axial
Q.19

Mechanical efficiency of a centrifugal pump is the ratio of

  • energy available at the impeller to the energy supplied to the pump by the prime mover
  • actual workdone by the pump to the energy supplied to the pump by the prime mover
  • energy supplied to the pump to the energy available at the impeller
  • manometric head to the energy supplied by the impeller per kN of water
Q.20

The hydraulic efficiency of a reaction turbine, is the ratio of

  • power produced by the turbine to the energy actually supplied by the turbine
  • actual work available at the turbine to energy imparted to the wheel
  • workdone on the wheel to the energy (or head of water) actually supplied to the turbine
  • none of the above
Q.21

The overall efficiency for a Pelton wheel lies between

  • 0.50 to 0.65
  • 0.65 to 0.75
  • 0.75 to 0.85
  • 0.85 to 0.90
Q.22

The unit power developed by a turbine is (where P = Power developed by the turbine under a head of water (H))

Q.23

The air vessel, in a reciprocating pump, is a cast iron closed chamber having an opening at its base.

  • Agree
  • Disagree
Q.24

A turbine is required to developkW atr.p.m. under a head ofm. Which of the following turbine should be used ?

  • Pelton wheel with one nozzle
  • Pelton wheel with two or more nozzles
  • Kaplan turbine
  • Francis turbine
Q.25

Which of the following pump is successfully used for lifting water from deep wells?

  • Centrifugal pump
  • Reciprocating pump
  • Jet pump
  • Air lift pump
Q.26

A hydraulic press is a device used

  • to store pressure energy which may be supplied to a machine later on
  • to increase the intensity of pressure of water by means of energy available from a large quantity of water at a low pressure
  • to lift larger load by the application of a comparatively much smaller force
  • all of the above
Q.27

Which of the following hydraulic unit is used for transmitting increased or decreased torque to the driven shaft?

  • Hydraulic ram
  • Hydraulic intensifier
  • Hydraulic torque converter
  • Hydraulic accumulator
Q.28

Braking jet in an impulse turbine is used

  • to break the jet of water
  • to bring the runner to rest in a short time
  • to change the direction of runner
  • none of these
Q.29

Which of the following hydraulic unit is used for transmitting increased or decreased torque to the driven shaft?

  • Hydraulic ram
  • Hydraulic intensifier
  • Hydraulic torque converter
  • Hydraulic accumulator
Q.30

Braking jet in an impulse turbine is used

  • to break the jet of water
  • to bring the runner to rest in a short time
  • to change the direction of runner
  • none of these
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