Practice Test: Question Set - 02
1. In a single casing, multistage pump running at constant speed, the capacity rating is to be slightly lowered. It can be done by
- (A) Designing new
impeller
- (B) Trimming the impeller
size to the required size by machining
- (C) Not possible
- (D) Some other
alterations in the impeller
2. Which of the following pump is successfully used for lifting water to the turbines?
- (A) Centrifugal
pump
- (B) Reciprocating
pump
- (C) Jet pump
- (D) Air
lift pump
3. If a pump is handling water and is discharging a certain flow Q at a constant total dynamic head requiring a definite B.H.P., the same pump when handling a liquid of specific gravity 0.75 and viscosity nearly same as of water , the horse power required will be
- (A) Same
- (B) 0.75 B.H.P.
- (C) B.H.P./0.75
- (D) 1.5 B.H.P.
4. A jet of water is striking at the centre of a curved vane moving with a uniform velocity in the direction of jet. For the maximum efficiency, the vane velocity is ________ of the jet velocity
- (A) One-half
- (B) One-third
- (C) Two-third
- (D) Three-fourth
5. In a centrifugal pump, the liquid enters the pump
- (A) At the top
- (B) At the bottom
- (C) At the canter
- (D) From sides
6. Kinematic similarity is said to exist between the model and the prototype, if both of them
- (A) Have
identical velocities
- (B) Are
equal in size and shape
- (C) Are
identical in shape, but differ only in size
- (D) Have
identical forces
7. For very high discharge at low pressure such as for flood control and irrigation applications, following type of pump is preferred
- (A) Centrifugal
- (B) Axial flow
- (C) Reciprocating
- (D) Mixed flow
8. The flow ratio of Francis turbine is defined as the ratio of the
- (A) Velocity
of flow at inlet to the theoretical jet velocity
- (B) Theoretical
velocity of jet to the velocity of flow at inlet
- (C) Velocity
of runner at inlet to the velocity of flow at inlet
- (D) None
of the above
9. The maximum number of jets generally employed in impulse turbine without jet interference is
- (A) 4
- (B) 6
- (C) 8
- (D) 12
10. The specific speed (Ns) of a centrifugal pump is given by
- (A) (N√Q)/H2/3
- (B) (N√Q)/H3/4
- (C) (N√Q)/H
- (D) (N√Q)/H5/4
11. Medium specific speed of turbine implies it is
- (A) Propeller turbine
- (B) Francis turbine
- (C) Impulse turbine
- (D) Any one of the above
12. A turbine is required to develop 1500 kW at 300 r.p.m. under a head of 150 m. Which of the following turbine should be used?
- (A) Pelton
wheel with one nozzle
- (B) Pelton
wheel with two or more nozzles
- (C) Kaplan
turbine
- (D) Francis
turbine
13. Puck up the wrong statement about centrifugal pump
- (A) Discharge a diameter
- (B) Head a speed²
- (C) Head a diameter
- (D) Power a speed⁴
14. The flow ratio in case of Francis turbine varies from
- (A) 0.15 to 0.3
- (B) 0.4 to 0.5
- (C) 0.6 to 0.9
- (D) 1 to 1.5
15. In reaction turbine, draft tube is used
- (A) To transport water
downstream without eddies
- (B) To convert the
kinetic energy to flow energy by a gradual expansion of the flow cross-section
- (C) For safety of turbine
- (D) To increase flow rate
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