# Hydraulics and Fluid Mechanics – Section 2

11. Reynold’s number is the ratio of inertia force to

A. pressure force
B. elastic force
C. gravity force
D. viscous force

Correct Answer: D. viscous force

12. The unit of dynamic viscosity in S.I. units is

A. N-m/s2
B. N-s/m2
C. poise
D. stoke

Correct Answer: B. N-s/m2

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

A. remains same
B. decreases
C. increases

Correct Answer: C. increases

14. The hydraulic gradient line may be above or below the center line of the pipe.

A. True
B. False

Correct Answer: B. False

15. A water tank contains 1.3 m deep water. The pressure exerted by the water per meter length of the tank is

A. 2.89 kN
B. 8.29 kN
C. 9.28 kN
D. 28.9 kN

Correct Answer: B. 8.29 kN

16. The specific gravity has no units.

A. Agree
B. Disagree

Correct Answer: A. Agree

17. The depth of water in a channel corresponding to the minimum specific energy is known as critical depth.

A. Agree
B. Disagree

Correct Answer: A. Agree

18. The ratio of the inertia force to the gravity force is called Froude number.

A. Agree
B. Disagree

Correct Answer: A. Agree

19. 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.

Correct Answer: C. The length of divergent portion in a venturimeter is equal to the convergent portion.

20. A vertically immersed surface is shown in the below figure. The distance of its center of pressure from the water surface is

Correct Answer: Option B