Fluid Mechanics MCQs

Question 1

Water hammer is caused, when water flowing in a pipe is suddenly brought to rest by closing the valve. The extent of pressure thus produced due to water hammer depends on the

Accepted Answer

All of the above

Answer

Pipe length

Answer

Fluid velocity in the pipe

Answer

Time taken to close the valve

Question 2

As per Newton's law of viscosity, the shear stress for a given rate of angular deformation of fluid is proportional to (where, $$\mu $$ = fluid viscosity)

Accepted Answer

$$\mu $$

Answer

$$\frac{1}{\mu }$$

Answer

$${\mu ^2}$$

Answer

$$\frac{1}{{{\mu ^2}}}$$

Question 3

Toothpaste is a

Accepted Answer

Dilatent

Answer

Bingham plastic

Answer

Pseudoplastic

Answer

Newtonion liquid

Question 4

Schedule number of a pipe, which is a measure of its wall thickness, is given by

Accepted Answer

1000 P'/S

Answer

100 P'/S

Answer

1000 S/P'

Answer

10000 P'/S

Question 5

Path followed by water jet issuing from the bottom of a water tank will be a

Accepted Answer

Parabola (vertex being at the opening)

Answer

Hyperbola

Answer

Horizontal straight line

Answer

Zig-zag path (which is geometrically undefined)

Question 6

Turbine impeller

Accepted Answer

Is effective over wide range of viscosities

Answer

Produces only radial current

Answer

Produces only tangential current

Answer

Does not produce tangential current

Question 7

Transition from laminar flow to turbulent flow is aided by the

Accepted Answer

All of the above

Answer

Surface roughness and curvature (i.e.sharp corners)

Answer

Vibration

Answer

Pressure gradient and the compressibility of the flowing medium

Question 8

Capillary tube method of viscosity measurement is based on the

Accepted Answer

Hagen-Poiseulle's equation

Answer

Stoke's law

Answer

Navier-stokes equation

Answer

None of these

Question 9

In power law, $$\zeta = {	ext{A}}{\left( {\frac{{{	ext{du}}}}{{{	ext{dy}}}}} ight)^2} + {	ext{B,}}$$ then the fluid is

Accepted Answer

Newtonian

Answer

Dilatant

Answer

Thixotropic

Answer

Rheopectic