# Fluid Mechanics 12

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

Subject: Fluid Mechanics 12

Part 6: List for questions and answers of Fluid Mechanics II

Q1. A triangular notch is preferred to a rectangular notch because
a) Its formula is simple to remember
b) It gives more accurate results for low discharge
c) It measures a wide range of flows accurately
d) All the above

Q2. The pressure less than atmospheric, pressure, is
a) Suction pressure
b) Vacuum pressure
c) Negative gauge pressure
d) All the above

Q3. A rise or fall of liquid in a glass tube of a very small diameter when dipped is
a) Directly proportional to the force per unit length of periphery
b) Directly proportional to the sine of the angle of contact
c) Directly proportional to the specific weight of liquid
d) Inversely proportional to the diameter of the glass tube

Q4. Pick up the incorrect statement from the following:
a) In radial flow, fluid flows such that pressure and velocity at any point change with
respect to its distance from the central axis
b) In radial flow, velocity of flow is in a radial direction
c) In radial flow, flow may take place radically inward to or outward from the centre
d) In radial flow, flow is one dimensional with stream lines parallel

Q5. Chezy’s formula is used to determine
a) Head loss due to friction in pipe
b) Velocity of flow in pipe
c) Velocity of flow in open channels
d) None of these

Q6. Frictional loss of head includes the loss of energy due to
a) Viscosity
b) Turbulence.
c) Both (a) and (b)
d) None of these

Q7. The length of hydraulic jump is roughly
a) 2 to 3 times its height
b) 3 to 5 times its height
c) 5 to 7 times its height
d) None of these

Q8. For a most economical trapezoidal open channel, the half of the top width must be equal to
a) The bed width
b) One sloping side
c) The depth of flow
d) None of these

Q9. The flow in open channel is said to be critical if the froude number is :
a) Less than 1.0
b) Equal to 1.0
c) Greater than 1.0
d) None of these

Q10. The imaginary line drawn such that the tangents at its all points indicate the direction of the velocity of the fluid particles at each point, is called
a) Path line
b) Stream line
c) Potential line
d) Streak line

Q11. A nozzle is fitted at the end of a pipe whose length is 320 m and diameter is 10 cm. If the value of f = 0.01, the diameter of the nozzle for the maximum transmission of power through the nozzle is
a) 2.4 cm
b) 2.5 cm
c) 2.6 cm
d) 2.7 cm

Q12. When the whole fluid mass rotates either due to fluid pressure or gravity or rotation previously imparted, the motion is known as
a) Free vortex
b) Forced vortex
c) Non-potential vortex
d) Rotational vortex

Q13. The shape of fire hose nozzle is generally kept
a) Divergent
b) Convergent
c) Convergent divergent
d) Cylindrical

Q14. Pick up the correct statement from the following:
a) For maximum velocity of flow, the depth of water in the circular channel must be
0.81 times the diameter of the channel
b) For maximum velocity, the hydraulic mean depth must be 0.3 times the diameter of circular channel
c) For maximum discharge the depth of flow must be 0.95 times the diameter of
circular channel
d) All the above

Q15. Weber number is the ratio of inertia force to
a) Surface tension
b) Gravitational force
c) Viscosity
d) Bouncy

Q16. Though angle of deviation of liquid is more in internal mouth piece, the contraction of the jet, is
a) More in the internal mouth piece
b) Less in the internal mouth piece
c) Equal to external mouth piece
d) None of these

Q17. An open container filled with water is moved vertically upward with a uniform linear acceleration. The pressure at its bottom will be
a) Greater than static pressure
b) Equal to static pressure
c) Lesser than static pressure
d) None of these

Q18. The flow in which each liquid particle has a definite path and the paths of adjacent particles do not cross each other, is called
a) Stream line flow
b) Uniform flow
d) Turbulent flow

Q19. In a two dimensional flow if the components of the velocity are u = ax ; v = by, the point where no motion occurs, is known as
a) Critical point
b) Stagnation point
c) Stationary point
d) None of these

Q20. Pick up the incorrect statement from to following regarding triangular notch:
a) For measuring low discharge, it gives more accurate result
b) Only one reading (i.e. H) is required for computation of discharge
c) Ventilation is necessary
d) None of these

Part 6: List for questions and answers of Fluid Mechanics II