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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

Correct Answer :

C. 241.5 r.p.m.


Related Questions

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4

Multistage centrifugal pumps are used to

A. Give high discharge

B. Produce high heads

C. Pump viscous fluids

D. All of these

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4

The optimum value of vane exit angle for a centrifugal pump impeller is

A. 10-15°

B. 20-25°

C. 30-40°

D. 50-60°

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4

Mechanical 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

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

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

The discharge through a reaction turbine with increase in unit speed

A. Increases

B. Decreases

C. Remain unaffected

D. First increases and then decreases

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4

The function of guide vanes in a reaction turbine is to

A. Allow the water to enter the runner without shock

B. Allow the water to flow over them, without forming eddies

C. Allow the required quantity of water to enter the turbine

D. All of the above

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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

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 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

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

A hydraulic ram is a device used to

A. Store the energy of water

B. Increase the pressure of water

C. To lift water from deep wells

D. To lift small quantity of water to a greater height when a large quantity of water is available at a smaller height

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4

Runaway speed of a hydraulic turbine is

A. Full load speed

B. The speed at which turbine runner will be damaged

C. The speed if the turbine runner is allowed to revolve freely without load and with the wicket gates wide open

D. The speed corresponding to maximum overload permissible

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4

The power produced by the reaction turbine is ________ to the head of water.

A. Directly proportional

B. Inversely proportional

C. 4th power

D. None of these

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4

Manometric head, in case of a centrifugal pump, is equal to

A. Suction lift + Loss of head in suction pipe due to friction + Delivery lift + Loss of head in delivery pipe due to friction + Velocity head in the delivery pipe

B. Workdone per kN of water Losses within the impeller

C. Energy per kN at outlet of impeller Energy per kN at inlet of impeller

D. All of the above

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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

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

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

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4

Power required to drive a centrifugal pump is directly proportional to ________ of its impeller.

A. Diameter

B. Square of diameter

C. Cube of diameter

D. Fourth power of diameter

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4

In a Kaplan 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

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

The discharge through a reaction turbine ________ with the increase in unit speed.

A. Decreases

B. Increases

C. Remain same

D. None of these

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4

The number of buckets on the periphery of a Pelton wheel is given by

A. (D/2d) + 5

B. (D/2d) + 10

C. (D/2d) + 15

D. (D/2d) + 20

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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 type of centrifugal pump preferred for a specific speed of 20 r.p.m. is

A. Slow speed pump with radial flow at outlet

B. Medium speed pump with radial flow at outlet

C. High speed pump with radial flow at outlet

D. High speed pump with axial flow at outlet

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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

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

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

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

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