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4

The flow rate in gear pump

A. Increases with increase in pressure

B. Decreases with increase in pressure

C. More or less remains constant with increase in pressure

D. Unpredictable

Correct Answer :

C. More or less remains constant with increase in pressure


Related Questions

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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

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

Centrifugal 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

Which of the following pump is successfully used for lifting water to the turbines?

A. Centrifugal pump

B. Reciprocating pump

C. Jet pump

D. Air lift pump

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4

By fitting an air vessel to the reciprocating pump, there is always a saving of work done and subsequently saving of power. The saving in case of a double acting reciprocating pump is

A. 39.2 %

B. 48.8 %

C. 84.8 %

D. 88.4 %

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4

The specific speed of turbine is defined as the speed of a unit

A. Of such a size that it delivers unit discharge at unit head

B. Of such a size that it delivers unit discharge at unit power

C. Of such a size that it requires unit power per unit head

D. Of such a size that it produces unit horse power with unit head

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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

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

In order to avoid cavitation in centrifugal pumps

A. The suction pressure should be high

B. The delivery pressure should be high

C. The suction pressure should be low

D. The delivery pressure should be low

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4

Puck up the wrong statement about centrifugal pump

A. Discharge a diameter

B. Head a speed²

C. Head a diameter

D. Power a speed⁴

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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

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

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

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

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

A. P/ √H

B. P/ H

C. P/ H3/2

D. P/ H²

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4

The force exerted by a jet of water impinging normally on a plate which due to the impact of jet, moves in the direction of jet with a velocity v is

A. [wa (V - v)]/2g

B. [wa (V - v)]/g

C. [wa (V - v)²]/2g

D. [wa (V - v²)]/g

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4

Which of the following turbine is preferred for 0 to 25 m head of water?

A. Pelton wheel

B. Kaplan turbine

C. Francis turbine

D. None of these

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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

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

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 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

Which of the following statement is wrong?

A. The reaction turbines are used for low head and high discharge.

B. The angle of taper on draft tube is less than 8°.

C. An impulse turbine is generally fitted slightly above the tail race.

D. A Francis turbine is an impulse turbine.

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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

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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

A hydraulic accumulator is a device used to store ________ energy which may be supplied to a machine later on.

A. Strain

B. Pressure

C. Kinetic

D. None of these

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4

A double overhung Pelton wheel has

A. Two jets

B. Two runners

C. Four jets

D. Four runners

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4

The hydraulic efficiency of an impulse turbine is maximum when velocity of wheel is _______ of the jet velocity,

A. One-fourth

B. One-half

C. Three-fourth

D. Double

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4

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

A. Radial

B. Axial

C. Centrifugal

D. Vortex

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4

Which of the following pump is preferred for flood control and irrigation applications?

A. Centrifugal pump

B. Axial flow pump

C. Mixed flow pump

D. Reciprocating pump