Questions and Answers Section 1

Questions and Answers

Question :

01.The runaway speed of a hydraulic turbine is the speed

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at which the turbine will run freely without load.

Note:-A water turbine is a rotary machine that converts kinetic energy and potential energy of water into mechanical work.

Question :

02.The efficiency of a centrifugal pump will be maximum when the blades are

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bent backward.

Note:-

Centrifugal pumps are used to transport fluids by the conversion of rotational kinetic energy to the hydrodynamic energy of the fluid flow.




Question :

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

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Axial flow pump

Note:-

An axial-flow pump, or AFP, is a common type of pump that essentially consists of a propeller (an axial impeller) in a pipe.

Question :

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

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Kaplan turbine.

Note:-

The Kaplan turbine is a propeller-type water turbine which has adjustable blades.

Question :

05.A hydraulic coupling belongs to the category of 

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energy transfer machines

Note:-

A fluid coupling or hydraulic coupling is a hydrodynamic device used to transmit rotating mechanical power. It has been used in automobile transmissions as an alternative to a mechanical clutch.

Question :

06.A reciprocating pump is suitable for

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less discharge and higher heads

 

Note:-

A reciprocating pump is a class of positive-displacement pumps which includes the piston pump, plunger pump and diaphragm pump.

Question :

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

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Francis turbine.

Note:-

It is an inward-flow reaction turbine that combines radial and axial flow concepts. Francis turbines are the most common water turbine in use today. They operate in a water head from 40 to 600 m (130 to 2,000 ft) and are primarily used for electrical power production.

 

Question :

08.Slip of a reciprocating pump is negative, when

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

Note:-

Slip is the quantity of fluid that leaks from the higher-pressure discharge to the lower-pressure suction. Slip occursbecause all rotary pumps require clearances between the rotating elements and pump housing.

Question :

09.Impulse turbine is generally fitted

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little above the tail race.

 

Note:-

a fast-flowing stretch of a river or stream below a dam or watermill.

Question :

10.The angle of taper on draft tube is

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less than 8°.

 

Note:-

function of a draft tube

 

Draft tube: The draft tube is a conduit which connects the runner exit to the tail race where the water is being finally discharged from the turbine. The primary function of the draft tube is to reduce the velocity of the discharged water to minimize the loss of kinetic energy at the outlet.