# Fluid Mechanics Test Questions - Set 2

1)   Which of the following statements are true for dimensional analysis?

1. The functional relationship between dependent and non-dependent variables can be expressed into dimensionless terms by dimensional analysis
2. In model testing, it reduces the number of variables into three numbers
3. It is used to change the theoretical equation into dimensionless form
4. It helps to convert the units of quantities from one system to another system

a. (1), (2) and (3)
b. (2), (3) and (4)
c. (1), (3) and (4)
d. (1), (2), (3) and (4)
 Answer  Explanation  Related Ques ANSWER: (1), (2), (3) and (4) Explanation: No explanation is available for this question!

2)   The unit of physical quantity which does not depend on the unit of any other physical quantity is called as

a. independent dimension
b. fundamental dimension
c. core dimension
d. none of the above
 Answer  Explanation  Related Ques ANSWER: fundamental dimension Explanation: No explanation is available for this question!

3)   Which of the following is not a primary quantity?

a. Mass (M)
b. Temperature (θ)
c. Time (T)
d. None of the above
 Answer  Explanation  Related Ques ANSWER: None of the above Explanation: No explanation is available for this question!

4)   What are the dimensions of force?

a. [M L T – 2 ]
b. [M L T – 1 ]
c. [M L 2 T – 2 ]
d. [M L 2 T 2 ]
 Answer  Explanation  Related Ques ANSWER: [M L T – 2 ] Explanation: No explanation is available for this question!

5)   Which of the following quantities has the dimensions [M0 L0 T 0]

a. Density
b. Stress
c. Strain
d. Strain Rate
 Answer  Explanation  Related Ques ANSWER: Strain Explanation: No explanation is available for this question!

6)   How is the intensity of shear stresses over the boundary layer?

a. small
b. large
c. sometimes small and sometimes large
d. cannot say
 Answer  Explanation  Related Ques ANSWER: large Explanation: No explanation is available for this question!

7)   The velocity gradients over the boundary layer are

a. small
b. large
c. sometimes small and sometimes large
d. cannot say
 Answer  Explanation  Related Ques ANSWER: large Explanation: No explanation is available for this question!

8)   What is the effect of free stream velocity on thickness of boundary layer?

a. Increase in free stream velocity increases the boundary layer thickness
b. Increase in free stream velocity decreases the boundary layer thickness
c. The boundary layer thickness does not get affected by any change in free stream velocity
d. unpredictable
 Answer  Explanation  Related Ques ANSWER: Increase in free stream velocity decreases the boundary layer thickness Explanation: No explanation is available for this question!

9)   If viscosity of fluid is more, the thickness of boundary layer is

a. more
b. less
c. not affected by change in viscosity
d. unpredictable
 Answer  Explanation  Related Ques ANSWER: more Explanation: No explanation is available for this question!

10)   The region in the turbulent boundary layer zone, adjacent to the solid surface of the plate is called as

a. laminar sub layer
b. turbulent sub layer
c. solid sub layer
d. solid layer
 Answer  Explanation  Related Ques ANSWER: laminar sub layer Explanation: No explanation is available for this question!

11)   Newton's law of viscosity states that

a. the shear stress applied to the fluid is directly proportional to the velocity gradient (du/dy)
b. the shear stress applied to the fluid is inversely proportional to the velocity gradient (du/dy)
c. the shear stress applied to the fluid is directly proportional to the specific weight of the fluid
d. the shear stress applied to the fluid is inversely proportional to the specific weight of the fluid
 Answer  Explanation  Related Ques ANSWER: the shear stress applied to the fluid is directly proportional to the velocity gradient (du/dy) Explanation: No explanation is available for this question!

12)   What is an ideal fluid?

a. A fluid which has no viscosity
b. A fluid which is incompressible
c. A fluid which has no surface tension
d. All of the above
 Answer  Explanation  Related Ques ANSWER: All of the above Explanation: No explanation is available for this question!

13)   The below diagram is a graph of change in shear stress with respect to velocity gradient in a fluid. What is a type of the fluid? a. Newtonian fluid
b. Non-Newtonian fluid
c. Ideal fluid
d. Dilatent fluid
 Answer  Explanation  Related Ques ANSWER: Non-Newtonian fluid Explanation: No explanation is available for this question!

14)   The fluid will rise in capillary when the capillary is placed in fluid, if

a. the adhesion force between molecules of fluid and tube is less than the cohesion between liquid molecules
b. the adhesion force between molecules of fluid and tube is more than the cohesion between liquid molecules
c. the adhesion force between molecules of fluid and tube is equal to the cohesion between liquid molecules
d. cannot say
 Answer  Explanation  Related Ques ANSWER: the adhesion force between molecules of fluid and tube is more than the cohesion between liquid molecules Explanation: No explanation is available for this question!

15)   When the angle between surface tension with the liquid (θ) is greater than 90o, the liquid becomes

a. flat
b. concave upward
c. convex upward
d. unpredictable
 Answer  Explanation  Related Ques ANSWER: convex upward Explanation: No explanation is available for this question!

16)   If stream function (Ψ) satisfies the Laplace equation, it is a possible case of

a. a circular flow
b. a rotational flow
c. an irrotational flow
d. none of the above
 Answer  Explanation  Related Ques ANSWER: an irrotational flow Explanation: No explanation is available for this question!

17)   Which acceleration has a nonzero value in uniform flow?

a. Local acceleration
b. Convective acceleration
c. Both local as well as convective acceleration
d. unpredictable
 Answer  Explanation  Related Ques ANSWER: Local acceleration Explanation: No explanation is available for this question!

18)   Viscous forces are not present in

a. rotational flow
b. irrotational flow
c. laminar flow
d. none of the above
 Answer  Explanation  Related Ques ANSWER: irrotational flow Explanation: No explanation is available for this question!

19)   The component of acceleration due to change in the direction of velocity vector is called as

a. direction acceleration
b. tangential acceleration
c. normal acceleration
d. cannot say
 Answer  Explanation  Related Ques ANSWER: normal acceleration Explanation: No explanation is available for this question!

20)   Blood circulation through arteries is

a. a laminar flow
b. a turbulent flow

 Answer  Explanation  Related Ques ANSWER: a laminar flow Explanation: No explanation is available for this question!

21)   What is the correct formula for Euler's equation of motion?

Where,
ρ = density of the fluid
p = pressure force
g = acceleration due to gravity
v = velocity of the fluid

a. (∂p / ρ) + (∂g / ρ) + (∂v / ρ) = 0
b. (∂p / ρ) + (∂g / ρ) + (v dv) = 0
c. (∂p / ρ) + (g dz) + (v dv) = 0
d. (p dp) + (g dz) + (v dv) = 0
 Answer  Explanation  Related Ques ANSWER: (∂p / ρ) + (g dz) + (v dv) = 0 Explanation: No explanation is available for this question!

22)   Which of the following sentences are true for Bernoulli's equation?

1. Bernoulli's principle is applicable to ideal incompressible fluid
2. The gravity force and pressure forces are only considered in Bernoulli's principle
3. The flow of fluid is rotational for Bernoulli's principle
4. The heat transfer into or out of fluid should be zero to apply Bernoulli's principle

a. (1), (2) and (3)
b. (1), (3) and (4)
c. (1), (2) and (4)
d. (1), (2), (3) and (4)
 Answer  Explanation  Related Ques ANSWER: (1), (2) and (4) Explanation: No explanation is available for this question!

23)   Which of the following devices does not use Bernoulli's equation as its working principle?

a. Venturimeter
b. Orifice-meter
c. Pitot tube
d. None of the above
 Answer  Explanation  Related Ques ANSWER: None of the above Explanation: No explanation is available for this question!

24)   Venturimeter consists of short converging conical tube which has a total inclination angle of

a. 11 ± 1o
b. 21 ± 1o
c. 30 ± 1o
d. 60 ± 1o
 Answer  Explanation  Related Ques ANSWER: 21 ± 1o Explanation: No explanation is available for this question!

25)   The cylindrical portion of short length, which connects converging and diverging section of venturimeter, is called as

a. diffuser
b. connector
c. throat
d. manometer tube
 Answer  Explanation  Related Ques ANSWER: throat Explanation: No explanation is available for this question!