Hydraulic Machines-Fluid Machineries - Set 04 - ObjectiveBooks
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# Practice Test: Question Set - 04

1. Saving of work done and power by fitting an air vessel to double acting reciprocating pump is of the order of
(A) 39.2%
(B) 49.2%
(C) 68.8%
(D) 84.8%

2. If the net positive suction head (NPSH) requirement for the pump is not satisfied, then
(A) No flow will take place
(B) Cavitation will be formed
(C) Efficiency will be low
(D) Excessive power will be consumed

3. According to fan laws, at constant pressure, the speed capacity and power vary
(A) Directly as the air or gas density
(B) Inversely as square root of density
(C) Inversely as density
(D) As square of density

4. Which of the following turbine is preferred for a specific speed of 60 to 300 r.p.m.?
(A) Pelton wheel
(B) Francis turbine
(C) Kaplan turbine
(D) None of these

5. The angle of taper on draft tube is
(A) Greater than 15°
(B) Greater than 8°
(C) Greater than 5°
(D) Less than 8°

6. The width of the bucket for a Pelton wheel is generally ________ the diameter of jet.
(A) Double
(B) Three times
(C) Four times
(D) Five times

7. Which place in hydraulic turbine is most susceptible for cavitations?
(A) Inlet of draft rube
(B) Blade inlet
(C) Guide blade
(D) Penstock

8. Discharge of a centrifugal pump is (where N = Speed of the pump impeller)
(A) Directly proportional to N
(B) Inversely proportional to N
(C) Directly proportional to
(D) Inversely proportional to

9. The discharge through a reaction turbine with increase in unit speed
(A) Increases
(B) Decreases
(C) Remain unaffected
(D) First increases and then decreases

10. The power produced by the reaction turbine is ________ to the head of water.
(A) Directly proportional
(B) Inversely proportional
(C) 4th power
(D) None of these

11. The maximum number of jets, generally, employed in an impulse turbine without jet interference are
(A) Two
(B) Four
(C) Six
(D) Eight

12. Pressure intensifier increases the pressure in proportion to
(A) Ratio of diameters
(B) Square of ratio of diameters
(C) Inverse ratio of diameters
(D) Square of inverse ratio of diameters

13. The specific speed from 160 to 500 r.p.m. of a centrifugal pump indicates that the pump is
(A) Slow speed with radial flow at outlet
(B) Medium speed with radial flow at outlet
(C) High speed with radial flow at outlet
(D) High speed with axial flow at outlet

14. For centrifugal pump impeller, the maximum value of the vane exit angle is
(A) 10° to 15°
(B) 15° to 20°
(C) 20° to 25°
(D) 25° to 30°

15. A hydraulic accumulator normally consists of
(A) Two cylinders, two rams and a storage device
(B) A cylinder and a ram
(C) Two coaxial rams and two cylinders
(D) A cylinder, a piston, storage tank and control valve

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