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4

The specific speed (Ns) of a centrifugal pump is given by

A. (N√Q)/H2/3

B. (N√Q)/H3/4

C. (N√Q)/H

D. (N√Q)/H5/4

Correct Answer :

B. (N√Q)/H3/4


Related Questions

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4

Which of the following statement is correct?

A. In an impulse turbine, the water impinges on the buckets with pressure energy.

B. In a reaction turbine, the water glides over the moving vanes with kinetic energy.

C. In an impulse turbine, the pressure of the flowing water remains unchanged and is equal to atmospheric pressure.

D. In a reaction turbine, the pressure of the flowing water increases after gliding over the vanes.

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4

The mechanical efficiency of an impulse turbine is

A. Ratio of the actual power produced by the turbine to the energy actually supplied by the turbine

B. Ratio of the actual work available at the turbine to the energy imparted to the wheel

C. Ratio of the Work done on the wheel to the energy of the jet

D. None of the above

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4

The overall efficiency for a Pelton wheel lies between

A. 0.50 to 0.65

B. 0.65 to 0.75

C. 0.75 to 0.85

D. 0.85 to 0.90

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4

Maximum impulse will be developed in hydraulic ram when

A. Waste valve closes suddenly

B. Supply pipe is long

C. Supply pipe is short

D. Ram chamber is large

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4

The speed ratio in case of Francis turbine varies from

A. 0.15 to 0.3

B. 0.4 to 0.5

C. 0.6 to 0.9

D. 1 to 1.5

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4

Low specific speed of turbine implies it is

A. Propeller turbine

B. Francis turbine

C. Impulse turbine

D. Any one of the above

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4

If the ratios of all the corresponding linear dimensions are equal, then the model and the prototype are said to have

A. Geometric similarity

B. Kinematic similarity

C. Dynamic similarity

D. None of these

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4

The width of the bucket for a Pelton wheel is generally ________ the diameter of jet.

A. Double

B. Three times

C. Four times

D. Five times

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4

Head developed by a centrifugal pump is

A. Proportional to diameter of impeller

B. Proportional to speed of impeller

C. Proportional to diameter and speed of impeller

D. None of the above

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4

According to fan laws, at constant weight of air or gas, the speed, capacity and pressure vary

A. Directly as the air or gas density

B. Inversely as square root of density

C. Inversely as density

D. As square of density

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4

In an inward flow reaction turbine

A. The water flows parallel to the axis of the wheel

B. The water enters at the centre of the wheel and then flows towards the outer periphery of the wheel

C. The water enters the wheel at the outer periphery and then flows towards the centre of the wheel

D. The flow of water is partly radial and partly axial

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4

Multistage centrifugal pumps are used to obtain

A. High discharge

B. High head

C. Pumping of viscous fluids

D. High head and high discharge

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4

The ratio of quantity of liquid discharged per second from the pump to the quantity of liquid passing per second through the impeller is known as

A. Manometric efficiency

B. Mechanical efficiency

C. Overall efficiency

D. Volumetric efficiency

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4

The unit speed of the turbine runner is

A. N/√H

B. N/H

C. N/H3/2

D. N/H²

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4

Impulse turbine is generally fitted

A. At the level of tail race

B. Little above the tail race

C. Slightly below the tail race

D. About 2.5 m above the tail race to avoid cavitations.

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4

According to fan laws, at constant pressure, the speed capacity and power vary

A. Directly as the air or gas density

B. Inversely as square root of density

C. Inversely as density

D. As square of density

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4

Dynamic similarity is said to exist between the model and the prototype, if both of them

A. Have identical velocities

B. Are equal in size and shape

C. Are identical in shape, but differ only in size

D. None of the above

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4

The Fourneyron turbine is _________ reaction turbine.

A. An axial flow

B. An inward flow

C. An outward flow

D. A mixed flow

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4

An impulse turbine is used for

A. Low head of water

B. High head of water

C. Medium head of water

D. High discharge

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4

The depth of the bucket for a Pelton wheel is generally ________ the diameter of jet.

A. Equal to

B. 1.2 times

C. 1.8 times

D. Double

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4

In an outward flow reaction turbine

A. The water flows parallel to the axis of the wheel

B. The water enters at the centre of the wheel and then flows towards the outer periphery of the wheel

C. The water enters the wheel at the outer periphery and then flows towards the centre of the wheel

D. The flow of water is partly radial and partly axial

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4

Indicator diagram of a reciprocating pump is a graph between

A. Flow vs. swept volume

B. Pressure in cylinder vs. swept volume

C. Flow vs. speed

D. Pressure vs. speed

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4

High specific speed of a pump implies it is

A. Centrifugal pump

B. Mixed flow pump

C. Axial flow pump

D. Any one of the above

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4

The power developed by a turbine is (where H = Head of water under which the turbine is working)

A. Directly proportional to H1/2

B. Inversely proportional to H1/2

C. Directly proportional to H3/2

D. Inversely proportional to H3/2

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4

The runaway speed of a hydraulic turbine is the speed

A. At full load

B. At which there will be no damage to the runner

C. Corresponding to maximum overload permissible

D. At which the turbine will run freely without load

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4

A turbine pump is basically a centrifugal pump equipped additionally with

A. Adjustable blades

B. Backward curved blades

C. Vaned diffusion casing

D. Inlet guide blades

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4

The efficiency of a Pelton wheel working under constant head ________ with the increase in power.

A. Remain same

B. Increases

C. Decreases

D. None of these

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4

Which of the following pump is generally used to pump highly viscous fluid?

A. Centrifugal pump

B. Reciprocating pump

C. Air lift pump

D. Screw pump

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4

In a Francis turbine runner, the numbers of blades are generally between

A. 2 to 4

B. 4 to 8

C. 8 to 16

D. 16 to 24

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4

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

A. Lift and resultant force

B. Drag and resultant force

C. Lift and tangential force

D. Lift and drag