# Fluid Kinematics and Dynamics MCQs with Answers

### MODULE 3: FLUID KINEMATICS & DYNAMICS

1. The value of bulk modulus of a fluid is required to determine
A. Reynold’s number
B. Froude’s number
C. Mach number
D. Euler’s number

2. In one dimensional flow, the flow
B. takes place in straight line
C. takes place in curve
D. takes place in one direction

3. According to equation of continuity,
A. w1a1 = w2a2
B. w1v1 = w2v2
C. a1v1 = a2v2
D. a1/v1 = a2/v2

4. Euler’s equation in the differential form for the motion of liquids is given by

C. ρ.dp + g.dz + v.dv = 0

5. An ideal fluid is frictionless and incompressible.
A. Correct
B. Incorrect

6. A flow in which the volume of a fluid and its density does not change during the flow is called
__________ flow.
A. incompressible
B. compressible

7. The Bernoulli’s equation is based on the assumption that
A. there is no loss of energy of the liquid flowing
B. the velocity of flow is uniform across any cross-section of the pipe
C. no force except gravity acts on the fluid
D. all of the above

8. The velocity corresponding to Reynold number of 2800, is called
A. sub-sonic velocity
B. super-sonic velocity
C. lower critical velocity
D. higher critical velocity

9. A flow in which __________ force is dominating over the viscosity is called turbulent flow.

A. elastic
B. surface tension
C. viscous
D. inertia

10. Bulk modulus of a fluid __________ as the pressure increases.
A. remains same
B. decreases
C. increases

11. Which of the following statement is wrong?
A. A flow whose streamline is represented by a curve, is called two dimensional flow.
B. The total energy of a liquid particle is the sum of potential energy, kinetic energy and pressure energy.
C. The length of divergent portion in a venturimeter is equal to the convergent portion.
D. A pitot tube is used to measure the velocity of flow at the required point in a pipe.

12. The loss of pressure head in case of laminar flow is proportional to
A. velocity
B. (velocity)2
C. (velocity)3
D. (velocity)4

13. The flow of water through the hole in the bottom of a wash basin is an example of

B. uniform flow
C. free vortex
D. forced vortex

14. In a footstep bearing, if the speed of the shaft is doubled, then the torque required to overcome the viscous resistance will be
A. double
B. four times
C. eight times
D. sixteen times

15. The velocity at which the laminar flow stops, is known as
A. velocity of approach
B. lower critical velocity
C. higher critical velocity
D. none of these

16. When a cylindrical vessel, containing some liquid, is rotated about its vertical axis, the liquid surface is depressed down at the axis of its rotation and rises up near the walls of the vessel on all sides. This type of flow is known as
B. turbulent flow
C. vortex flow
D. uniform flow

17. The Euler’s equation for the motion of liquids is based upon the assumption that
A. the fluid is non – viscous, homogeneous and incompressible
B. the velocity of flow is uniform over the section
C. the flow is continuous, steady and along the stream line
D. all of the above

18 The shear stress-strain graph for a newtonian fluid is a
A. straight line
B. parabolic curve
C. hyperbolic curve
D. elliptical

19. A flow in which each liquid particle does not have a definite path and the paths of individual particles also cross each other, is called turbulent flow.
A. Agree
B. Disagree

20. A flow in which the viscosity of fluid is dominating over the inertia force is called
C. laminar flow
D. turbulent flow

21. Bulk modulus of a fluid __________ as the pressure increases.

A. remains same
B. decreases
C. increases

22. Which of the following statement is wrong?
A. A flow whose streamline is represented by a curve, is called two dimensional flow.
B. The total energy of a liquid particle is the sum of potential energy, kinetic energy and pressure energy.
C. The length of divergent portion in a venturimeter is equal to the convergent portion.
D. A pitot tube is used to measure the velocity of flow at the required point in a pipe.

23. Laminar flow __________ place at very low velocities.
A. takes
B. does not take

24. The velocity at which the laminar flow stops, is known as
A. velocity of approach
B. lower critical velocity
C. higher critical velocity
D. none of these

25. The Euler’s equation for the motion of liquids is based upon the assumption that
A. the fluid is non – viscous, homogeneous and incompressible
B. the velocity of flow is uniform over the section
C. the flow is continuous, steady and along the stream line

D. all of the above

26. The shear stress-strain graph for a newtonian fluid is a
A. straight line
B. parabolic curve
C. hyperbolic curve
D. elliptical

27. A flow in which the viscosity of fluid is dominating over the inertia force is called
C. laminar flow
D. turbulent flow

28. An air vessel is provided at the summit in a syphon to
A. avoid interruption in the flow
B. increase discharge
C. increase velocity
D. maintain pressure difference

29. Viscous force is the __________ of shear stress due to viscosity and cross-sectionar area of flow.
A. sum
B. different
C. product
D. ratio

30. A flow through an expanding tube at increasing rate is called unsteady non-uniform flow.
A. Yes
B. No

31. Which of the following statement is correct ?
A. In a compressible flow, the volume of the flowing liquid changes during the flow.
B. A flow in which the volume of the flowing liquid does not change, is called incompressible flow.
C. When the particles rotate about their own axes while flowing, the flow is said to be rotational flow.
D. all of the above

32. A flow is called sub-sonic, if the Mach number is
A. less than unity
B. unity
C. between 1 and 6
D. more than 6

33. For a perfect incompressible liquid, flowing in a continuous stream, the total energy of a particle remains the same, while the particle moves from one point to another. This statement is called
A. continuity equation
B. Bernoulli’s equation
C. Pascal’s law
D. Archimede’s principle

34. The ratio of velocity of fluid in an undisturbed stream to the velocity of sound wave is known as Mach number.
A. Yes
B. No

35. When a cylindrical vessel containing liquid is revolved, the surface of the liquid takes the shape of
A. a triangle
B. a paraboloid
C. an ellipse
D. none of these

36. The imaginary line drawn in the fluid in such a way that the tangent to any point gives the direction of motion at that point, is known as
A. path line
B. stream line
C. steak line
D. potential line

37. A flow whose streamline is represented by a curve, is called
A. one-dimensional flow
B. two-dimensional flow
C. three-dimensional flow
D. four-dimensional flow

38. When the Mach number is less than unity, the flow is called
A. sub-sonic flow
B. sonic flow
C. super-sonic flow
D. hyper-sonic flow

39. A flow whose streamline is represented by a straight line, is called __________ dimensional flow.
A. one
B. two
C. three
D. four

40. The variation in the volume of a liquid with the variation of pressure is called its
A. surface tension
B. compressibility
C. capillarity
D. viscosity

41. When the Mach number is between __________ the flow is called super-sonic flow.
A. 1 and 2.5
B. 2.5 and 4
C. 4 and 6
D. 1 and 6