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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

Correct Answer :

D. 16 to 24


Related Questions

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4

Overall efficiency of a centrifugal pump is the ratio of

A. Energy available at the impeller to the energy supplied to the pump by the prime mover

B. Actual workdone by the pump to the energy supplied to the pump by the prime mover

C. Energy supplied to the pump to the energy available at the impeller

D. Manometric head to the energy supplied by the impeller per kN of water

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4

A Francis turbine is used when the available head of water is

A. 0 to 25 m

B. 25 m to 250 m

C. Above 250 m

D. None of these

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4

The impeller of a centrifugal pump may have

A. Volute casing

B. Volute casing with guide blades

C. Vortex casing

D. Any one of these

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4

The maximum number of jets generally employed in impulse turbine without jet interference is

A. 4

B. 6

C. 8

D. 12

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4

Axial flow pump is started with its delivery valve

A. Kept fully closed

B. Kept fully open

C. Irrespective of any position

D. Kept 50% open

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4

In a reaction turbine, the draft tube is used

A. To run the turbine full

B. To prevent air to enter the turbine

C. To increase the head of water by an amount equal to the height of the runner outlet above the tail race

D. To transport water to downstream

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4

Discharge of a centrifugal pump is

A. Directly proportional to diameter of its impeller

B. Inversely proportional to diameter of its impeller

C. Directly proportional to (diameter)² of its impeller

D. Inversely proportional to (diameter)² of its impeller

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4

A turbine develops 10000 kW under a head of 25 metres at 135 r.p.m. Its specific speed is

A. 175.4 r.p.m.

B. 215.5 r.p.m.

C. 241.5 r.p.m.

D. 275.4 r.p.m

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4

The specific speed of a turbine is the speed of an imaginary turbine, identical with the given turbine, which

A. Delivers unit discharge under unit head

B. Delivers unit discharge under unit speed

C. Develops unit power under unit head

D. Develops unit power under unit speed

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4

Which type of the pump is different from others in the same group?

A. Screw pump

B. Gear pump

C. Cam and piston pump

D. Plunger pump

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4

The speed of a turbine runner is

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

A jet of water is striking at the centre of a curved vane moving with a uniform velocity in the direction of jet. For the maximum efficiency, the vane velocity is ________ of the jet velocity

A. One-half

B. One-third

C. Two-third

D. Three-fourth

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4

The discharge of a double acting reciprocating pump is (where L = Length of stroke, A = Cross-sectional area of piston, and N = Speed of crank in r.p.m.)

A. L.A.N

B. 2 L.A.N

C. (L.A.N)/60

D. (2 L.A.N)/60

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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

The unit discharge through the turbine is

A. Q/√H

B. Q/H

C. Q/H3/2

D. Q/H²

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4

The hydraulic efficiency of an impulse turbine is the

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

Low specific speed of a pump implies it is

A. Centrifugal pump

B. Mixed flow pump

C. Axial flow pump

D. None of the above

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4

When a piping system is made up primarily of friction head and very little of vertical lift, then pump characteristics should be

A. Horizontal

B. Nearly horizontal

C. Steep

D. First rise and then fall

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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

In a single casing, multistage pump running at constant speed, the capacity rating is to be slightly lowered. It can be done by

A. Designing new impeller

B. Trimming the impeller size to the required size by machining

C. Not possible

D. Some other alterations in the impeller

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4

The static head of a centrifugal pump is equal to the ________ of suction head and delivery head.

A. Product

B. Difference

C. Sum

D. None of these

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4

Slip of a reciprocating pump is negative, when

A. Suction pipe is short and pump is running at low speeds

B. Delivery pipe is long and pump is running at high speeds

C. Suction pipe is short and delivery pipe is long and the pump is running at low speeds

D. Suction pipe is long and delivery pipe is short and the pump is running at high speeds

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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

Geometric 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. Have identical forces

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4

The specific speed of a turbine is given by the equation

A. N√P / H3/2

B. N√P / H²

C. N√P / H5/4

D. N√P / H3

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4

A Pelton wheel is

A. Tangential flow impulse turbine

B. Inward flow impulse turbine

C. Outward flow impulse turbine

D. Inward flow reaction turbine

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4

In a reciprocating pump, air vessels are used to

A. Smoothen the flow

B. Reduce suction head

C. Increase delivery head

D. Reduce acceleration head

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4

If a pump is handling water and is discharging a certain flow Q at a constant total dynamic head requiring a definite B.H.P., the same pump when handling a liquid of specific gravity 0.75 and viscosity nearly same as of water, the horse power required will be

A. Same

B. 0.75 B.H.P.

C. B.H.P./0.75

D. 1.5 B.H.P.

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4

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

A. Air lift pump

B. Jet pump

C. Hydraulic coupling

D. Hydraulic press

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4

Reciprocating pumps are no more to be seen in industrial applications (in comparison to centrifugal pumps) because of

A. High initial and maintenance cost

B. Lower discharge

C. Lower speed of operation

D. Necessity of air vessel