Fluid Mechanics – Multiple Choice Questions (MCQ) and Answers – Set 2

Fluid Mechanics – Multiple Choice Questions (MCQ) and Answers – Set 2


1-If a cylindrical wooden pole, 20 cm in diameter, and 1 m in height is placed in a pool of water in a vertical position (the gravity of wood is 0.6), then it will

(A) Float in stable equilibrium

(B) Float in unstable equilibrium

(C) Float in neutral equilibrium

(D) Start moving horizontally

(Ans: B)


2-An open tank contains water to depth of 2m and oil over it to a depth of 1m. If the specific gravity of oil is 0.8, then the pressure intensity at the interface of the two fluid layers will be

(A) 7848 N/m^2

(B) 8720 N/m^2

(C) 9747 N/m^2

(D) 9750 N/m^2

(Ans: A)


3-Consider the following statements

For a body totally immersed in a fluid

I-The weight acts through the centre of gravity of the body

II-The up thrust acts through the centroid of the body

Of these statements

(A) Both I and II are true

(B) I is true but II is false

(C) I is false but II is true

(D) Neither I nor II is true

(Ans: A)


4-A simple Pitot tube can be used to measure which of the following quantities?

I-Static head

II-Datum head

III-Dynamic head

IV-Friction head

V-Total head

Select the correct answer using the codes given below

(A) I, II and IV

(B) I, III and V

(C) II, III and IV

(D) II, III and V

(Ans: B)


5-The shear stress in turbulent flow is

(A) Linearly proportional to the velocity gradient

(B) Proportional to the square of the velocity gradient

(C) Dependent on the mean velocity of flow

(D) Due to the exchange of energy between the molecules

(Ans: A)


6-Consider the following statements regarding a plane area submerged in a liquid:

I-The total force is the product of specific weight of the liquid, the area and the depth of its centroid

II-The total force is the product of the area and the pressure at its centroid

Of these statements

(A) I alone is correct

(B) II alone is correct

(C) Both I and II are false

(D) Both I and II are correct

(Ans: D)


7-The buoyant force acting on a floating body passes through the

(A) Metacentre of the body

(B) Centre of gravity of the body

(C) Centroid of volume of the body

(D) Centroid of the displaced volume

(Ans: B)


8-Which one of the following sets of conditions clearly apply to an ideal fluid?

(A) Viscous and compressible

(B) Non viscous and incompressible

(C) Non viscous and compressible

(D) Viscous and incompressible

(Ans: B)


9-For flow through a horizontal pipe, the pressure gradient dp/dx in the flow direction is

(A) +ve

(B) 1

(C) zero

(D) -ve

(Ans: D)


10-In a pipe flow, the heat lost due to friction is 6 m. If the power transmitted through the pipe has to be maximum then the total head at the inlet of the pipe will have to be maintained at

(A) 36 m

(B) 30 m

(C) 24 m

(D) 18 m

(Ans: D)