1. In order to avoid cavitation in centrifugal pumps
the suction pressure should be high
the delivery pressure should be high
the suction pressure should be low
the delivery pressure
✅ The correct answer is option A.
Hydraulic Machines MCQs
2. The power developed by a turbine is (where H = Head of water under which the turbine is working)
directly proportional to H1/2
inversely proportional to H1/2
directly proportional to H3/2
inversely proportional
✅ The correct answer is option C.
3. Braking jet in an impulse turbine is used
to break the jet of water
to bring the runner to rest in a short time
to change the direction of runner
none of these
✅ The correct answer is option B.
5. A Pelton wheel develops 1750 kW under a head of 100 metres while running at 200 r.p.m. and discharging 2500 litres of water per second. The unit speed of the wheel is
10 r.p.m.
20 r.p.m.
40 r.p.m.
80 r.p.m.
✅ The correct answer is option B.
6. In an axial flow reaction turbine, the water flows __________ to the axis of the wheel.
parallel
perpendicular
✅ The correct answer is option A.
7. In a Francis turbine, the pressure at inlet is __________ that at outlet.
less than
more than
✅ The correct answer is option B.
8. In a mixed flow reaction turbine, the flow of water is partly radial and partly axial.
Correct
Incorrect
✅ The correct answer is option A.
9. The width of the bucket for a Pelton wheel is generally __________ the diameter of jet.
double
three times
four times
five times
✅ The correct answer is option D.
10. In an impulse turbine, the pressure of water both at entering and leaving the vanes, is atmospheric.
Agree
Disagree
✅ The correct answer is option A.