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4

Motion of a liquid in a volute casing of a centrifugal pump is an example of

A. Rotational flow

B. Radial

C. Forced spiral vortex flow

D. Spiral vortex flow

Correct Answer :

D. Spiral vortex flow


Related Questions

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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

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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

A hydraulic intensifier normally consists of

A. Two cylinders, two rams and a storage device

B. A cylinder and a ram

C. Two coaxial rams and two cylinders

D. A cylinder, a piston, storage tank and control valve

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4

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

A. Centrifugal pump

B. Reciprocating pump

C. Jet pump

D. Airlift pump

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4

Specific speed for reaction turbines ranges from

A. 0 to 4.5

B. 10 to 100

C. 80 to 200

D. 250 to 300

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4

The maximum hydraulic efficiency of an impulse turbine is (where φ = Angle of blade tip at outlet)

A. (1 + cos φ)/2

B. (1 - cos φ)/2

C. (1 + sin φ)/2

D. (1 - sin φ)/2

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4

Head developed by a centrifugal pump depends on

A. Impeller diameter

B. Speed

C. Fluid density

D. Both (A) and (B) 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

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

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

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 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

Casting of a centrifugal pump is designed so as to minimize

A. Friction loss

B. Cavitations

C. Static head

D. Loss of kinetic energy

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4

Which of the following statement is correct as regard to water wheels?

A. They have slow speeds

B. They are suitable even for low water heads

C. They give constant efficiency, even if the discharge is not constant

D. All of the above

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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

Reaction turbines are used for

A. Low head

B. High head

C. High head and low discharge

D. Low head and high discharge

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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

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

A ship with jet propulsion draws water through inlet orifices at right angles to the direction of its motion. The propelling force of the jet is (where a = Area of the jet, Vr = Relative velocity of the jet and ship = V + v, v = Velocity of the ship, and V = Velocity of the jet issuing from the ship)

A. waVr /g × (Vr + v)

B. waVr /g × (Vr - v)

C. waVr /g × (Vr + v)²

D. waVr /g × (Vr - v)²

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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 centrifugal pumps, maximum efficiency is obtained when the blades are

A. Straight

B. Bent forward

C. Bent backward

D. Radial

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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

The ratio of actual work available at the turbine to the energy imparted to the wheel is known as ________ efficiency.

A. Hydraulic

B. Mechanical

C. Overall

D. None of these

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4

The maximum efficiency of jet propulsion of a ship with inlet orifices at right angles to the direction of motion of ship, is

A. 40 %

B. 50 %

C. 60 %

D. 80 %

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4

In impulse Turbine, energy available at the inlet is in the form of

A. Potential Energy

B. Strain Energy

C. Kinetic energy

D. None of these

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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 gross or total head of the turbine is the ________ of the water levels at the head race and tail race.

A. Sum

B. Difference

C. Product

D. None of these

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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 (where N = Speed of the pump impeller)

A. Directly proportional to N

B. Inversely proportional to N

C. Directly proportional to N²

D. Inversely proportional to N²

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4

For 450 m head of water, _________ shall be used.

A. Pelton wheel

B. Kaplan turbine

C. Francis turbine

D. None of these