Engineering Questions with Answers - Multiple Choice Questions
MCQs on Universal Velocity Distribution
1 - Question
What is an aspect ratio in universal velocity distribution?
a) b*h
b) b/h
c) b+h
d) b-h
View Answer
b
Explanation: Aspect ratio in universal velocity ratio is defined as the ratio of free surface of the fluid flow width to the depth of water. The formula is : Aspect ratio= b/h. It can also be defined as the ratio of span to the mean chord in an aero foil.
2 - Question
What is the ratio of maximum velocity to the average velocity when the fluid passes through two parallel plates?
a) 1/4
b) 1/2
c) 3/4
d) 1
View Answer
c
Explanation: The maximum velocity occurs at the centre. At the centre, the radius is equal to zero. The average velocity is obtained by dividing the discharge of fluid. The discharge takes place across the cross-sectional area of the pipe.
3 - Question
The Prandtl Number approximates ___________
a) Momentum diffusivity to thermal diffusivity
b) Thermal diffusivity to momentum diffusivity
c) Shear stress to thermal diffusivity
d) Thermal diffusivity to kinematic viscosity
View Answer
a
Explanation: The Prandtl number is a dimensionless number. It approximates the ratio of momentum diffusivity to thermal diffusivity. It can be expressed as Pr = v/ α(1). Where α= thermal diffusivity and v = momentum diffusivity.
4 - Question
Eddy viscosity is a turbulent transfer of_________
a) Fluid
b) Heat
c) Momentum
d) Pressure
View Answer
c
Explanation: Eddy viscosity is a turbulent transfer of momentum by eddies. It gives rise to an internal fluid friction. It is in analogous to the action of molecular viscosity in a laminar fluid flow. Eddy viscosity takes place on a large scale.
5 - Question
What is the function of transilient turbulence theory?
a) Parameterizing turbulence
b) Stopping turbulence
c) Initiating turbulence
d) Detecting turbulence
View Answer
a
Explanation: Transilient turbulence theory is the method used for parameterizing turbulence. Its main function is to allow all non-local vertical mixing between every pair of grid points. It happens in mainly in the vertical column.
6 - Question
What is the formula for kinematic eddy viscosity?
a) Eddy viscosity / kinematic viscosity
b) Eddy viscosity * kinematic viscosity
c) Eddy viscosity / mass density
d) Eddy viscosity / dynamic viscosity
View Answer
c
Explanation: Kinematic eddy viscosity is defined as the ratio between Eddy viscosity and mass density of the fluid. It happens mainly at one hundred times the molecular kinematic viscosity. It is in the order 1m2s-1.
7 - Question
Eddy diffusion happens due to_________
a) Eddy motion
b) Fluid motion
c) Water constraint
d) Eddy constraint
View Answer
a
Explanation: Eddy diffusion happens due to Eddy motion. This eddy motion is created due to fluid mixing. The fluid mixture causes the formation of eddies. Eddies can vary in size from small microscales to subtropical scales.
8 - Question
When is the fluid called laminar?
a) Reynolds number is greater than 2000
b) Reynolds number is less than 2000
c) The density of the fluid is high
d) Low viscosity
View Answer
b
Explanation: Reynolds number is a dimensionless quantity. It helps to predict the flow pattern in fluid mechanics. At low Reynolds number, the flow has a very low density, due to which the value of Reynolds number is less than 2000.
9 - Question
When is a fluid called turbulent?
a) Reynolds number is greater than 2000
b) Reynolds number is less than 2000
c) The density of the fluid is low
d) High viscosity of fluid
View Answer
a
Explanation: Reynolds number is a dimensionless quantity. It helps to predict the flow pattern in fluid mechanics. At high Reynolds number, the flow has a very high density, due to which the value of Reynolds number is greater than 2000.
10 - Question
Coefficient of friction of a laminar flow is_________
a) Re/16
b) Re/64
c) 16/Re
d) 64/Re
View Answer
c
Explanation: Coefficient of friction is defined as the value that shows relationship between force and the normal reaction. It is mainly used to find out an object’s normal force and frictional force. Thus, it is equal to 16/Re.