# Fluid Mechanics 11

Civil Engineering MCQ. PWD, CPWD, RRB, SSC, Mock Test Paper

Subject: Fluid Mechanics 11

Part 5: List for questions and answers of Fluid Mechanics II

Q1. Power required to drive a centrifugal pump is directly proportional to __________ of its impeller.
a) Diameter
b) Square of diameter
c) Cube of diameter
d) Fourth power of diameter

Q2. The mechanical efficiency of an impulse turbine is
a) Ratio of the actual power produced by the turbine to the energy actually supplied by the turbine
b) Ratio of the actual work available at the turbine to the energy imparted to the wheel
c) Ratio of the work done on the wheel to the energy of the jet
d) None of the above

Q3. In a kaplan turbine runner, the number of blades is generally between
a) 2 to 4
b) 4 to 8
c) 8 to l6
d) 16 to 24

Q4. The ratio of actual work available at the turbine to the energy imparted to the wheel is known as __________ efficiency.
a) Hydraulic
b) Mechanical
c) Overall
d) None

Q5. In a reaction turbine, the draft tube is used
a) To run the turbine full
b) To prevent air to enter the turbine
c) To increase the head of water by an amount equal to the height of the runner outlet above the tail race
d) To transport water to downstream

Q6. Which of the following pump is preferred for flood control and irrigation applications?
a) Centrifugal pump
b) Axial flow pump
c) Mixed flow pump
d) Reciprocating pump

Q7. The efficiency of a pelton wheel working under constant head ………….with the increase in power.
a) Remains same
b) Increases
c) Decreases
d) None

Q8. Which of the following turbine is preferred for 0 to 25 m head of water?
a) Pelton wheel
b) Kaplan turbine
c) Francis turbine
d) None of these

Q9. Work done by a turbine………….. upon the weight of water flowing per second.
a) Depends
b) Does not depend
c) None
d) None

Q10. The speed of an imaginary turbine, identical with the given turbine, which will develop a unit power under a unit head, is known as
a) Normal speed
b) Unit speed
c) Specific speed
d) None of these

Q11. 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°

Q12. The capacity of a hydraulic accumulator is generally specified as the maximum amount of energy stored.
a) True
b) False
c) Cant defined
d) None

Q13. The impeller of a centrifugal pump may have
a) Volute casing
b) Volute casing with guide blades
c) Vortex casing
d) Any one of these

Q14. 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

Q15. 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

Q16. A draft tube is used with impulse turbines.
a) Yes
b) No
c) Cant defined
d) None

Q17. The working of which of the following hydraulic units is based on Pascal’s law?
a) Air lift pump
b) Jet pump
c) Hydraulic coupling
d) Hydraulic press

Q18. In order to avoid cavitations in centrifugal pumps
a) The suction pressure should be high
b) The delivery pressure should be high
c) The suction pressure should be low
d) The delivery pressure should be low

Q19. In a mixed flow reaction turbine, the flow of water is partly radial and partly axial.
a) Correct
b) Incorrect
c) None
d) Cant defined

Q20. Which of the following pump is generally used to pump highly viscous fluid?
a) Centrifugal pump
b) Reciprocating pump
c) Air lift pump
d) Screw pump

Part 5: List for questions and answers of Fluid Mechanics II