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

Answer: Option D

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

Answer: Option B

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

Answer: Option C

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

Answer: Option B

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