store the energy of water
increase the pressure of water
to lift water from deep wells
to lift small quantity
✅ The correct answer is option D.
Hydraulic Machines MCQs
The cavitation in reaction turbines is avoided, to a great extent by
installing the turbine below the tail race level
using stainless steel runner of the turbine
providing highly polished blades to the runner
all of the above
✅ The correct answer is option D.
A turbine develops 10000 kW under a head of 25 metres at 135 r.p.m. Its specific speed is
175.4 r.p.m.
215.5 r.p.m.
241.5 r.p.m.
275.4 r.p.m
✅ The correct answer is option C.
The hydraulic efficiency of an impulse turbine is maximum when velocity of wheel is __________ of the jet velocity,
one-fourth
one-half
three-fourth
double
✅ The correct answer is option B.
The hydraulic efficiency of an impulse turbine is the
ratio of the actual power produced by the turbine to the energy actually supplied by the turbine
ratio of the actual work available at the turbine to the energy imparted to the wheel
ratio of the work done on the wheel to the energy of the jet
none of the above
✅ The correct answer is option C.
A Pelton wheel working under a constant head and discharge, has maximum efficiency when the speed ratio is
0.26
0.36
0, 46
0.56
✅ The correct answer is option C.
The speed ratio in case of Francis turbine varies from
0.15 to 0.3
0.4 to 0.5
0.6 to 0.9
1 to 1.5
✅ The correct answer is option C.
The action of a centrifugal pump is that of a reversed reaction turbine.
Correct
Incorrect
✅ The correct answer is option A.
If the ratio’s of the corresponding forces acting at corresponding points are equal, then the model and the prototype are said to have.
geometric similarity
kinematic similarity
dynamic similarity
none of these
✅ The correct answer is option C.
If the Francis turbine is run below 50 percent head for a long period, it will not only lose its efficiency but also the cavitation danger will become more serious.
Agree
Disagree
✅ The correct answer is option A.