The undershot water wheels are those in which – the wheel runs entirely by the Impulse of water

Breaking jet in an impulse turbine used to – to bring the runner to rest in short time

A reciprocating pump – requires air vessel.

A Pelton wheel is tangential flow impulse turbine

An impulse turbine used for – high head of water

The hydraulic efficiency of an impulse turbine is the – ratio of the work done on the wheel to the energy of the jet.

The mechanical efficiency of an impulse turbine is the ratio of the actual work available at the turbine to the energy imparted to the wheel

The hydraulic efficiency of an impulse turbine is maximum when velocity of wheel is one of the jet velocity one-half

He maximum hydraulic efficiency of an impulse turbine is – (1 + cos)/2

The overall efficiency of pelton  wheels lies between – 0.85 to 0.90

Double overhung pelton wheel has – two runners

The width of the  bucket for a Pelton wheel is generally the diameter of jet – 5 times

The depth of the bucket for a pelton wheel is generally the diameter of- 1.2 times

Jet ratio is defined as the ratio of the diameter of pelton wheel to the diameter of jet

 The number of packets on the Periphery of a pelton wheel is given by- D/2d+15

In an inward flow reaction turbine – the water enters the wheel at the outer Periphery and then flow towards the centre of the wheel

 Overall efficiency of a reaction turbine is the ratio of – power produced by the turbine to the energy actually supplied by the turbine

The Runaway speed of hydraulic turbine is the speed at which the turbine will run freely without load

The power developed by turbine is – directly proportional to H

the unit power developed by turbine is – P/H

The speed of turbine runner is directly proportional to – H

The unit of speed of the turbine runner is – N/H

The unit discharge through the turbine is – Q/H

The specific speed of turbine is given by the equation – NP

Which of the following turbine is preferred 40 to 25 m head of water –  Kaplan turbine

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

For 450 m head of water shall be used Pelton wheel

 A Pelton wheel working under a constant head and discharge has maximum efficiency when the speed ratio is 0.46

the Cavitation in a hydraulic machine is mainly due to – low pressure

multi-stage centrifugal pumps are used to produce – high heads

slip of reciprocating pump is defined as – the difference of theoretical discharge and the actual discharge

in a reciprocating pump air vessels are used to – reduce acceleration head

discharge of centrifugal pump is – directly proportional to N

Delivery head of centrifugal pump is directly proportional to N

For centrifugal pump  pump impeller the maximum value of the vane exit angle is 20 to 25 degree

which of the following is successfully used for lifting water from deep wells – air lift pump

 which of the following is successfully used for lifting water to the turbine – Jet pumps

Centrifugal pumps operating in series will result in – higher head

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