121. A centrifugal pump will start delivering liquid only when the pressure rise in the impeller is equal to the
kinetic head
velocity head
manometric head
static head
✅ The correct answer is option C.
Hydraulic Machines MCQs
122. Discharge of a centrifugal pump is (where N = Speed of the pump impeller)
directly proportional to N
inversely proportional to N
directly proportional to N2
inversely proportional to N2
✅ The correct answer is option A.
123. The ratio of actual work available at the turbine to the energy imparted to the wheel is known as __________ efficiency.
hydraulic
mechanical
overall
✅ The correct answer is option B.
124. The principle of jet propulsion is used in driving the ships and aeroplanes.
Correct
Incorrect
✅ The correct answer is option A.
125. Theoretical power required (in watts) to drive a reciprocating pump is (where w = Specific weight of liquid to be pumped in N/m3, Q = Discharge of the pump in m3/s, Hs = Suction head in metres, and Hd = Delivery head in metres)
wQHs
wQHd
wQ(Hs – Hd)
wQ(Hs + Hd)
✅ The correct answer is option D.
126. Discharge (Q) of a centrifugal pump is given by (where D = Diameter of impeller at inlet, b = Width of impeller at inlet, and Vf = Velocity of flow at inlet)
Q = π.D.Vf
Q = π.b.Vf
Q = π.D.b.Vf
Q = D.b.Vf
✅ The correct answer is option C.
127. Which of the following pump is preferred for flood control and irrigation applications?
Centrifugal pump
Axial flow pump
Mixed flow pump
Reciprocating pump
✅ The correct answer is option B.
128. The specific speed from 160 to 500 r.p.m. of a centrifugal pump indicates that the pump is
slow speed with radial flow at outlet
medium speed with radial flow at outlet
high speed with radial flow at outlet
high speed with axial flow at outlet
✅ The correct answer is option D.
129. Delivery head of water of a centrifugal pump is inversely proportional to diameter of its impeller.
Yes
No
✅ The correct answer is option B.
130. The power produced by the reaction turbine is __________ to the head of water.
directly proportional
inversely proportional
✅ The correct answer is option A.