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WorksheetsDay 52-Nov 13-Worksheet-PWD-Impact of jets,hydraulic machines
Total questions: 15
Worksheet time: 11mins
In an impulse turbine, the nozzle converts the entire pressure head into:
Pressure energy
Kinetic energy
Potential energy
Static energy
Pelton turbines are suitable for:
Low head, high discharge
Medium head, medium discharge
High head, low discharge
Low head, low discharge
Recommended speed ratio for Pelton wheel (bucket speed divided by jet velocity) is:
0.25 to 0.35
0.43 to 0.48
0.60 to 0.70
0.90 to 1.00
Francis turbine flow type (modern design) is:
Tangential flow
Axial flow
Mixed flow
Outward radial flow
Pumps connected in series are mainly used for increasing:
Discharge
Head
Efficiency
Suction lift
Kaplan turbine is a low head, high discharge turbine. True or False
True
False
For a jet acting on a moving flat plate, force depends on (V−u)2 . True or False
True
False
Assertion (A): Casing of a centrifugal pump converts kinetic energy into pressure energy. Reason (R): The casing has gradually increasing area which reduces velocity and increases pressure.
A and R are true and R explains A
A and R are true but R does not explain A
A true, R false
A false, R true
Net head equals gross head minus (a) .
………….. of a turbine is defined as the speed of a similar turbine producing 1 kW at a head of 1 meter.
(a)
Cavitation occurs when local pressure falls below (a) pressure of water.
Work done by a jet on a moving flat plate is force multiplied by (a) .
For a curved plate, force in the jet direction is proportional to (1+ ______).
cosine of the angle
sine of the angle
tangent of the angle
angle in degrees
A water jet of diameter 20 mm strikes a flat stationary plate normally at a velocity of 25 m/s. Density of water is 1000 kg/m3. Calculate the force on the plate.
(a)
A pump develops 18 m head. Three identical pumps are connected in series. Find total head.
(a)
