Hydraulics and Fluid Mechanics MCQ – Set 14

Are you guys looking for Mechanical Engineering MCQ Questions with Answers PDF Free Download as per Mechanical Engineeringnew exam pattern? You came to the right page. This may assist you to understand and check your knowledge about the Subjects. Students also can take a free test of the Multiple Choice Questions of Mechanical Engineering. Each question has four options followed by the right answer. These Mechanical Engineering MCQ Questions are selected supported by the newest exam pattern.


Q1. When a cylindrical vessel containing liquid is revolved about its vertical axis at a constant angular velocity, the pressure

(A) Varies as the square of the radial distance
(B) Increases linearly as its radial distance
(C) Increases as the square of the radial distance
(D) Decreases as the square of the radial distance

Answer: (A) Varies as the square of the radial distance


Q2. The velocity corresponding to Reynold number of 2800, is called

(A) Sub-sonic velocity
(B) Super-sonic velocity
(C) Lower critical velocity
(D) Higher critical velocity

Answer: (D) Higher criticalvelocity


Q3. The force present in a moving liquid is

(A) Inertia force
(B) Viscous force
(C) Gravity force
(D) All of these

Answer: (D) All of these


Q4. Whenever a plate is held immersed at some angle with the direction of flow of the liquid, it is subjected to some pressure. The component of this pressure, in the direction of flow of the liquid, is known as

(A) Lift
(B) Drag
(C) Stagnation pressure
(D) Bulk modulus

Answer: (B) Drag


Q5. In an external mouthpiece, the absolute pressure head at vena contracta is __ the atmospheric pressure head by an amount equal to 0.89 times the height of the liquid, above the vena contracta.

(A) Less than
(B) More than
(C) Equal to
(D) None of these

Answer: (A) Less than


Q6. Rain drops are spherical because of

(A) Viscosity
(B) Air resistance
(C) Surface tension forces
(D) Atmospheric pressure

Answer: (C) Surface tension forces


Q7. Flow occurring in a pipeline when a valve is being opened is

(A) Steady
(B) Unsteady
(C) Laminar
(D) Vortex

Answer: (B) Unsteady


Q8. Manometer is used to measure

(A) Pressure in pipes, channels etc.
(B) Atmospheric pressure
(C) Very low pressure
(D) Difference of pressure between two points

Answer: (A) Pressure in pipes, channels etc.


Q9. The discharge through an external mouthpiece is given by (where a = Cross-sectional area of the mouthpiece, and H = Height of liquid above the mouthpiece)

(A) 0.855 a.√(2gH)
(B) 1.855 aH.√(2g)
(C) 1.585 a.√(2gH)
(D) 5.85 aH.√(2g)

Answer: (A) 0.855 a.√(2gH)


Q10. According to Newton’s law of viscosity, the shear stress on a layer of a fluid is __ to the rate of shear strain.

(A) Equal to
(B) Directly proportional
(C) Inversely proportional
(D) None of these

Answer: (B) Directly proportional


Q11. The celerity (velocity) of a pressure wave in a fluid is given by (where K = Bulk modulus, and ρ = Density of the fluid)

(A) K.ρ
(B) K/ρ
(C) ρ/K
(D) None of these

Answer: (B) K/ρ


Q12. When the pressure intensity at a point is more than the local atmospheric pressure, then the difference of these two pressures is called

(A) Gauge pressure
(B) Absolute pressure
(C) Positive gauge pressure
(D) Vacuum pressure

Answer:(C) Positive gauge pressure


Q13. The unit of surface tension is

(A) N/m
(B) N/m2
(C) N/m3
(D) N-m

Answer: (A) N/m


Q14. Uniform flow occurs when

(A) The direction and magnitude of the velocity at all points are identical
(B) The velocity of successive fluid particles, at any point, is the same at successive periods of time
(C) The magnitude and direction of the velocity do not change from point to point in the fluid
(D) The fluid particles move in plane or parallel planes and the streamline patterns are identical in each pleasure

Answer: (C) The magnitude and direction of the velocity do not change from point to point in the fluid


Q15. 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.

Answer: (C) The length of divergent portion in a Venturimeter is equal to the convergent portion.


Q16. The resultant upward pressure of a fluid on a floating body is equal to the weight of the fluid displaced by the body. This definition is according to

(A) Buoyancy
(B) Equilibrium of a floating body
(C) Archimedes’ principle
(D) Bernoulli’s theorem

Answer: (C) Archimedes’ principle


Q17. The power transmitted through the pipe is maximum when the head lost due to friction is equal to

(A) One-fourth of the total supply head
(B) One-third of the total supply head
(C) One-half of the total supply head
(D) Two-third of the total supply head

Answer: (B) One-third of the total supply head


Q18. Property of a fluid by which its own molecules are attracted is called

(A) Adhesion
(B) Cohesion
(C) Viscosity
(D) Compressibility

Answer:(B) Cohesion


Q19. For a floating body to be in equilibrium

(A) Meta centre should be above e.g.
(B) Centre of buoyancy and e.g. must lie on same vertical plane
(C) A righting couple should be formed
(D) All of the above

Answer: (D) All of the above


Q20. A ship whose hull length is 100 m is to travel at 10 m/sec. For dynamic similarity, at what velocity should a 1:25 model be towed through water?

(A) 10 m/sec
(B) 25 m/sec
(C) 2 m/sec
(D) 50 m/sec

Answer:(C) 2 m/sec


We hope the given Mechanical Engineering MCQ Questions with Answers will definitely yield fruitful results. Hope you got enough ideas on the MCQs on Mechanical Engineering. If you have any queries related to Mechanical Engineering MCQs Multiple Choice Questions with Answers, drop your questions below and will get back to you in no time.