# FLUID MECHANICS MCQs 14 | ESE | GATE | GPSC | CIVIL ENGINEERING

1. Boundary layer thickness is the distance from the surface of the solid body in the direction perpendicular to flow where the velocity of fluid is equal to

[A] Free stream velocity
[B] 0.5 times the free stream velocity
[C] 0.9 times the free stream velocity
[D] 0.99 times the free stream velocity

2. To study the cruising of supersonic missiles in air by using dimensional analysis technique, which of the two dimensionless numbers will be of significance
[A] Reynolds number and Froude’s number
[B] Reynolds number and Mach number
[C] Weber number and Froude’s number
[D] Weber number and Mach number

3. The drag and lift forces experienced by object placed in a fluid stream are due to
[A] Pressure and turbulence
[B] Viscosity and turbulence
[C] Pressure and viscosity
[D] Pressure and gravity

4. Kinematic similarity between model and prototype means
[A] The similarity of forces
[B] The similarity of motion
[C] The similarity of shape
[D] The similarity of discharge

5. ___ is the square root of the ratio of the inertia force to the pressure force.
[A] Reynolds number
[B] Mach’s number
[C] Euler’s number
[D] Froude’s number