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4

In a centrifugal pump casing, the flow of water leaving the impeller, is

A. Rectilinear flow

B. Radial flow

C. Free vortex motion

D. Forced vortex

Correct Answer :

C. Free vortex motion


Related Questions

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4

The flow ratio of Francis turbine is defined as the ratio of the

A. Velocity of flow at inlet to the theoretical jet velocity

B. Theoretical velocity of jet to the velocity of flow at inlet

C. Velocity of runner at inlet to the velocity of flow at inlet

D. None of the above

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4

In axial flow fans and turbines, fluid enters and leaves as follows

A. Radially, axially

B. Axially, radially

C. Axially, axially

D. Radially, radially

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4

A hydraulic press is a device used

A. To store pressure energy which may be supplied to a machine later on

B. To increase the intensity of pressure of water by means of energy available from a large quantity of water at a low pressure

C. To lift larger load by the application of a comparatively much smaller force

D. All of the above

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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

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

In a centrifugal pump, the regulating valve is provided on the

A. Casing

B. Delivery pipe

C. Suction pipe

D. Impeller

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4

Saving of work done and power by fitting an air vessel to double acting reciprocating pump is of the order of

A. 39.2 %

B. 49.2 %

C. 68.8 %

D. 84.8 %

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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 would discharge

A. Same quantity of liquid

B. 0.75 Q

C. Q/0.75

D. 1.5 Q

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4

Which of the following pump is suitable for small discharge and high heads?

A. Centrifugal pump

B. Axial flow pump

C. Mixed flow pump

D. Reciprocating pump

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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

Which of the following statement is correct?

A. The centrifugal pump is suitable for large discharge and smaller heads.

B. The centrifugal pump requires less floor area and simple foundation as compared to reciprocating pump.

C. The efficiency of centrifugal pump is less as compared to reciprocating pump.

D. All of the above

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4

The force exerted by a jet of water (in a direction normal to flow) impinging on a fixed plate inclined at an angle θ with the jet is

A. waV/2g × sinθ

B. waV/g × sinθ

C. waV²/2g × sin2θ

D. waV²/g × sinθ

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4

The maximum number of jets, generally, employed in an impulse turbine without jet interference are

A. Two

B. Four

C. Six

D. Eight

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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 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 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

Power required (in watts) to drive a centrifugal pump is (where Hm = Manometric head in metres, w = Specific weight in N/m3, Q = Discharge of the pump in m3/s, and ηo = Overall efficiency of the pump)

A. (w Hm) / (Q × ηo)

B. (w Hm Q) / ηo

C. (w Q) / (Hm × ηo)

D. (w Q ηo) / Hm

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4

Hydraulic accumulator is used for

A. Accumulating oil

B. Supplying large quantities of oil for very short duration

C. Generally high pressures to operate hydraulic machines

D. Supplying energy when main supply fails

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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

Saving of work done and power by fitting an air vessel to single acting reciprocating pump is of the order of

A. 39.2 %

B. 49.2 %

C. 68.8 %

D. 84.8 %

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4

The discharge through a turbine 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

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

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

Which of the following is not an impulse turbine?

A. Girad turbine

B. Turgo turbine

C. Pelton wheel

D. Kaplan turbine

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4

If the net positive suction head (NPSH) requirement for the pump is not satisfied, then

A. No flow will take place

B. Cavitation will be formed

C. Efficiency will be low

D. Excessive power will be consumed

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4

For very high discharge at low pressure such as for flood control and irrigation applications, following type of pump is preferred

A. Centrifugal

B. Axial flow

C. Reciprocating

D. Mixed flow

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4

Which of the following turbine is preferred for a specific speed of 60 to 300 r.p.m.?

A. Pelton wheel

B. Francis turbine

C. Kaplan turbine

D. None of these

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4

The angle of taper on draft tube is

A. Greater than 15°

B. Greater than 8°

C. Greater than 5°

D. Less than 8°

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4

A turbine is required to develop 1500 kW at 300 r.p.m. under a head of 150 m. Which of the following turbine should be used?

A. Pelton wheel with one nozzle

B. Pelton wheel with two or more nozzles

C. Kaplan turbine

D. Francis turbine

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4

A Pelton wheel develops 1750 kW under a head of 100 metres while running at 200 r.p.m. and discharging 2500 litres of water per second. The unit power of the wheel is

A. 0.25 kW

B. 0.75 kW

C. 1.75 kW

D. 3.75 kW