Fluid Mechanics Multiple Choice Questions (MCQ)

Fluid Mechanics Multiple Choice Questions (MCQ) for Competitive Examinations. Objective type Questions and Answers on Fluid Mechanics.

1- An ideal fluid is one which is

(A) non-viscous

(B) in-compressible

(C) in-compressible and no internal resistance to flow

(D) non-viscous and friction-less


2- If the velocity, pressure and density do not change at a point with respect to time, the flow is called

(A) Uniform flow

(B) Eulerian flow

(C) Lagrangian flow

(D) Steady flow


3- According to Newton’s law of viscosity, shear stress is

(A) directly proportional to the velocity

(B) inversely proportional to the velocity

(C) directly proportional to the velocity gradient

(D) directly proportional to viscosity


4- Bernoulli’s equation can be derived from the principle of

(A) Conservation of Mass

(B) Conservation of Energy

(C) Conservation of Momentum

(D) Conservation of Pressure


5-The point about which a floating body starts oscillating when the body is tilted is called:

(A) center of buoyancy

(B) center of gravity

(C) center of pressure

(D) metacentre


6- Stoke’s law deals with

(A) settling of fine particles

(B) turbulent flow between the parallel plates

(C) laminar flow between the parallel plates

(D) laminar flow in the tubes


7- The magnitude of water hammer is dependent on

(A) the length of the pipe line

(B) the elastic properties of the fluid passing through the pipe

(C) the speed at which the valve is closed

(D) All of the above


8- Hygrometer is used for estimating

(A) water vapor content of air

(B) water content of soil

(C) capillary potential of soil water

(D) specific gravity of a liquid


9- For a submerged body, if the center of buoyancy is above the center of gravity, the equilibrium is called as

(A) stable equilibrium

(B) unstable equilibrium

(C) neutral equilibrium

(D) restoring equilibrium


10- The instrument used for measuring evaporation is:

(A) hygrometer

(B) atmometer

(C) lysimeter

(D) luxmeter


11- The boundary layer exists in which of the following?

(A) Flow of real fluids

(B) Flow of ideal fluids

(C) Flow over flat surfaces only

(D) Pipe flow only


12- In case of turbulent flow, the loss of head is approximately proportional to

(A) Velocity

(B) (velocity)1/2

(C) (velocity)3/4

(D) (velocity)2


13- Euler number is related to

(A) Inertia force and pressure force

(B) Inertia force and elastic force

(C) Inertia force and viscous force

(D) Inertia force and gravity force


14- Hydraulic Gradient Line represents the sum of

(A) Pressure Head and kinetic Head

(B) Kinetic Head and Elevation Head

(C) Pressure Head, Kinetic Head and Elevation Head

(D) Pressure Head and Elevation Head


15- The range of coefficient of discharge for a venturi meter is

(A) 0.5 to 0.7

(B) 0.7 to 0.8

(C) 08. to 0.9

(D) 0.95 to 0.99


16- Weber number is a ratio of

(A) Surface tension force to inertia force

(B) Surface tension force to elastic force

(C) Inertia force to surface tension force

(D) Elastic force to surface tension force


17- In a submerged body, when the center of gravity is above the center of buoyancy, the body is in

(A) Unstable equilibrium

(B) Stable equilibrium

(C) Neutral equilibrium

(D) Natural equilibrium


18- Floats are used to measure

(A) Discharge of stream

(B) Velocity of stream

(C) Flood discharge

(D) Afflux


19- The ratio of the inertia and viscous forces acting in any flow ignoring other forces is called

(A) Euler number

(B) Froude number

(C) Reynolds number

(D) Weber number


20- Bourdon gauge measures

(A) Absolute pressure

(B) Gauge pressure

(C) Local atmospheric pressure

(D) Standard atmospheric pressure



1-(C), 2-(D), 3-(C), 4-(B), 5-(D), 6-(A), 7-(D), 8-(A), 9-(A), 10-(B), 11-(A), 12-(D), 13-(A), 14-(D), 15-(D), 16-(C), 17-(A), 18-(B), 19-(C), 20-(B)