Hydraulic Machines
31. In axial flow fans and turbines, fluid enters and leaves as follows
- radially, axially
- axially, radially
- axially, axially
- radially, radially
- combination of axial and radial.
Correct answer: (C)
axially, axially
32. In centrifugal pumps, maximum efficiency is obtained when the blades are
- straight
- bent forward
- bent backward
- radial
- given aerofoil section.
Correct answer: (C)
bent backward
33. In reaction turbine, draft tube is used
- to transport water downstream without eddies
- to convert the kinetic energy to flow energy by a gradual expansion of the flow cross-section
- for safety of turbine
- to increase flow rate
- none of the above.
Correct answer: (B)
to convert the kinetic energy to flow energy by a gradual expansion of the flow cross-section
34. Indicator diagram of a reciprocating pump is a graph between
- flow vs swept volume
- pressure in cylinder vs swept volume
- flow vs speed
- pressure vs speed
- swept volume vs speed.
Correct answer: (B)
pressure in cylinder vs swept volume
35. Low specific speed of a pump implies it is
- centrifugal pump
- mixed flow pump
- axial flow pump
- any one of the above
- none of the above.
Correct answer: (A)
centrifugal pump
36. Low specific speed of turbine implies it is
- propeller turbine
- Francis turbine
- impulse turbine
- any one of the above
- none of the above.
Correct answer: (C)
impulse turbine
37. Maximum impulse will be developed in hydraulic ram when
- waste valve closes suddenly
- supply pipe is long
- supply pipe is short
- ram chamber is large
- supply pipe has critical diameter,
Correct answer: (A)
waste valve closes suddenly
38. Medium specific speea of turbine implies it is
- propeller turbine
- Francis turbine
- impulse turbine
- any one of the above
- none of the above.
Correct answer: (B)
Francis turbine
39. Medium specific speed of a pump implies it is
- centrifugal pump
- mixed flow pump
- axial flow pump
- any one of the above
- none of the above.
Correct answer: (B)
mixed flow pump
40. Motion of a liquid in a volute casing of a centrifugal pump is an example of
- rotational flow
- radial
- forced spiral vortex flow
- forced cylindrical vortex flow
- spiral vortex flow.
Correct answer: (E)
spiral vortex flow.