Hydraulic Machines(Engineering > Mechanical Engineering ) Questions and Answers
Question 1. The working of which of the following hydraulic units is based on Pascal's law?
Air lift pump
Jet pump
Hydraulic coupling
Hydraulic press
Explanation:-
Answer: Option D. -> Hydraulic press Answer: (d).Hydraulic press
Question 2. The hydraulic efficiency of a reaction turbine, is the ratio of
power produced by the turbine to the energy actually supplied by the turbine
actual work available at the turbine to energy imparted to the wheel
workdone on the wheel to the energy (or head of water) actually supplied to the turbine
none of the above
Explanation:-
Answer: Option C. -> workdone on the wheel to the energy (or head of water) actually supplied to the turbine Answer: (c).workdone on the wheel to the energy (or head of water) actually supplied to the turbine
Question 3. A hydraulic intensifier is a device used to increase the intensity of pressure of water by means of energy available from a large quantity of water at a low pressure.
Correct
Incorrect
Can't say
None of these
Explanation:-
Answer: Option A. -> Correct Answer: (a).Correct
Question 4. By fitting an air vessel to the reciprocating pump, there is always a saving of work done and subsequently saving of power.The saving in case of a double acting reciprocating pump is
39.2%
48.8%
84.8%
88.4%
Explanation:-
Answer: Option A. -> 39.2% Answer: (a).39.2%
Question 5. 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 should be low
Explanation:-
Answer: Option A. -> the suction pressure should be high Answer: (a).the suction pressure should be high
Question 6. The maximum hydraulic efficiency of an impulse turbine is (where φ = Angle of blade tip at outlet)
(1 + cos φ)/2
(1 - cos φ)/2
(1 + sin φ)/2
(1 - sin φ)/2
Explanation:-
Answer: Option A. -> (1 + cos φ)/2 Answer: (a).(1 + cos φ)/2
Question 7. In a centrifugal pump, the water enters the impeller __________ and leaves the vanes axially.
axially
radially
Can't say
None of these
Explanation:-
Answer: Option B. -> radially Answer: (b).radially
Question 8. In a Francis turbine runner, the number of blades are generally between
2 to 4
4 to 8
8 to 16
16 to 24
Explanation:-
Answer: Option D. -> 16 to 24 Answer: (d).16 to 24
Question 9. The relation between hydraulic efficiency (ηh), mechanical efficiency (ηm) and overall efficiency (ηo) ) is
ηh = ηo x ηm
ηm = ηo x ηh
ηo = ηh x ηm
none of these
Explanation:-
Answer: Option C. -> ηo = ηh x ηm Answer: (c).ηo = ηh x ηm
Question 10. A Kaplan turbine is an axial flow reaction turbine.
