Top 1000+ Solved Fluid Mechanics (FM) MCQ Questions Answer
Q. Coefficient of velocity is defined as the ratio of
a. Actual velocity of jet at vena contracta to the theoretical velocity
b. Area of jet at vena contracta to the area of orifice
c. Actual discharge through an orifice to the theoretical discharge
d. None of the above
Q. The mass of 2.5 m3 of a certain liquid is 2 tonnes. Its mass density is
a. 200 kg/m3
b. 400 kg/m3
c. 600 kg/m3
d. 800 kg/m3
Q. Free surface of a liquid tends to contract to the smallest possible area due to force of
a. Surface tension
b. Viscosity
c. Friction
d. Cohesion
Q. When a cylindrical vessel containing liquid is revolved about its vertical axis at a constantangular velocity, the pressure
a. Varies as the square of the radial distance
b. Increases linearly as its radial distance
c. Increases as the square of the radial distance
d. Decreases as the square of the radial distance
Q. A large Reynold number is indication of
a. Smooth and streamline flow
b. Laminar flow
c. Steady flow
d. Highly turbulent flow
Q. The total pressure on the top of a closed cylindrical vessel completely filled up with a liquid is
a. Directly proportional to (radius)2
b. Inversely proportional to (radius)2
c. Directly proportional to (radius)4
d. Inversely proportional to (radius)4
Q. For pipes, turbulent flow occurs when Reynolds number is
a. Less than 2000
b. Between 2000 and 4000
c. More than 4000
d. Less than 4000
Q. The shear stress-strain graph for a Newtonian fluid is a
a. Straight line
b. Parabolic curve
c. Hyperbolic curve
d. Elliptical
Q. The region between the separation streamline and the boundary surface of the solid body isknown as
a. Wake
b. Drag
c. Lift
d. Boundary layer
Q. The fluid forces considered in the Navier Stokes equation are
a. Gravity, pressure and viscous
b. Gravity, pressure and turbulent
c. Pressure, viscous and turbulent
d. Gravity, viscous and turbulent
Q. Select the wrong statement
a. An equivalent pipe is treated as an ordinary pipe for all calculations
b. The length of an equivalent pipe is equal to that of a compound pipe
c. The discharge through an equivalent pipe is equal to that of a compound pipe
d. The diameter of an equivalent pipe is equal to that of a compound pipe
Q. A flow through a long pipe at constant rate is called
a. Steady uniform flow
b. Steady non-uniform flow
c. Unsteady uniform flow
d. Unsteady non-uniform flow
Q. The velocity at which the flow changes from laminar flow to turbulent flow is called
a. Critical velocity
b. Velocity of approach
c. Sub-sonic velocity
d. Super-sonic velocity
Q. According to Darcy's formula, the loss of head due to friction in the pipe is (where f = Darcy'scoefficient, l = Length of pipe, v = Velocity of liquid in pipe, and d = Diameter of pipe)
a. flv²/2gd
b. flv²/gd
c. 3flv²/2gd
d. 4flv²/2gd
Q. The loss of pressure head in case of laminar flow is proportional to
a. Velocity
b. (Velocity)2
c. (Velocity)3
d. (Velocity)4