Engineering Questions with Answers - Multiple Choice Questions
Mechanical Operations MCQ’s – Filtration Introduction
1 - Question
As the solids are deposited, the cake resistance will ______
a) Decrease
b) Increase
c) Constant
d) Stable
View Answer
Answer: b
Explanation: The resistance of filter cake will increase as solids are deposited but the other resistances will remain constant throughout the process.
2 - Question
What does the below equation represents?
a) Velocity of cake
b) Velocity of filtrate
c) Velocity of discharge
d) Invalid relation
View Answer
Answer: b
Explanation: If dP is the pressure difference across a small thickness dl of cake, the velocity of flow of the filtrate, where r is specific resistance of filter cake.
3 - Question
What is an optimum speed of a basket centrifuge?
a) 100 to 500 rpm
b) 800 to 1800 rpm
c) 1500 to 2000 rpm
d) 200 to 500 rpm
View Answer
Answer: b
Explanation: The speed of the basket is so high 800 to 1800 rpm and the load great often over 1000 pounds, if the basket shaft on fixed bearings.
4 - Question
Centrifuge and automatic discharges are used for ________
a) Crystalline and product removal
b) Amorphous and feed removal
c) Crystalline and feed removal
d) Amorphous and product removal
View Answer
Answer: a
Explanation: When the centrifuge is used for handling materials as crystalline products, automatic dischargers are used for removing the product.
5 - Question
The unloading time depends upon the _________
a) Torque
b) Radial
c) Axial
d) Longitudinal
View Answer
Answer: a
Explanation: The unloading time depends upon the torque available for turning the basket at unloading speed.
6 - Question
The power requirements ________ at unloading.
a) Decrease
b) Increase
c) Constant
d) Stable
View Answer
Answer: b
Explanation: The power requirements increases during the unloading since power is utilized by the basket as well as the unloader knife.
7 - Question
In a conical screen filter, the liquid is impelled through a _________
a) Centrifuge
b) Torque
c) Escaper
d) Desolater
View Answer
Answer: a
Explanation: When a conical screen is rotated about its axis, centrifuge force will impel a liquid through the openings in the screen.
8 - Question
________ the steepest angle at which a sloping surface formed of loose material.
a) Angle of nip
b) Angle of crutch
c) Angle of Dump
d) Angle of repose
View Answer
Answer: d
Explanation: The angle of repose or critical angle of repose of a granular material is the steepest angle of descent relative to the horizontal plane.
9 - Question
Suppose the particles of a sump are sliding across a cone, which of the following is true?
a) Cos Ө = α
b) Cos Ө/2 < α
c) Ө = α
d) Ө/2 > α
View Answer
Answer: d
Explanation: If the half angle of cone screen is greater than the angle of repose of the solids, the solids will slide across with velocity of independent feed rate.
10 - Question
If angle of repose is too low, then velocity is _________
a) Constant
b) Low
c) High
d) Optimum
View Answer
Answer: c
Explanation: If the angle is too great, this velocity will be too high and the retention time under centrifugal force will be too short.