Engineering Questions with Answers - Multiple Choice Questions
Mechanical Operations MCQ’s – Comparison of Sedimentation and Centrifuge
1 - Question
Sphericity of a cubical particle, when its equivalent diameter is taken as height of the cube is ______
a) 0.5
b) 1
c) 20.5
d) 30.5
View Answer
Answer: b
Explanation: The ratio of surface area to the volume is defined as the Sphericity, thus if the height is taken as diameter the Sphericity is unity.
2 - Question
Mass flow of a granular solid (M) through a circular opening of diameter, D follows ___
a) M directly proportional to D0.5
b) M directly proportional to D2
c) M directly proportional to D3
d) M directly proportional to D
View Answer
Answer: c
Explanation: For a particle having a granular solid structure, when passes the opening the essential quantity is seen as to be volume i.e. D3.
3 - Question
For a non-spherical particles, the sphericity __________
a) The ratio of sphere area to the actual surface area
b) Has the dimension of the length
c) Always less than 1
d) Greater than 1
View Answer
Answer: a
Explanation: The ratio of surface area of a sphere having same volume as the particle to the actual surface area of the particle which is sphericity for non-spherical particles.
4 - Question
The inlet pressure in a constant rate filtration _____
a) Increases continuously
b) Decreases continuously
c) Remains constant
d) No effect
View Answer
Answer: a
Explanation: As the process of filtration moves forward with the time, the cake resistance increases and thus due to this pressure also increases.
5 - Question
200 mesh screen mean 200 opening per_______
a) cm2
b) inch
c) cm
d) inch2
View Answer
Answer: c
Explanation: According to Tyler’s standard the mesh is referred as the number of opening per length of the sieve or screen.
6 - Question
Flow of filtrate through the cake in plate and frame filter press is best described by the ______ equation.
a) Kozney Carman
b) Hagen Poiseullie
c) Fanning
d) Kremse
View Answer
Answer: a
Explanation: Kozney Carman gave an equation to calculate the pressure drop in a packed bed for solids, this equation was only valid for laminar flow.
7 - Question
Apron conveyors are used for _________
a) Heavy loads and short runs
b) Small loads and long runs
c) Heavy loads and small runs
d) Small load and small runs
View Answer
Answer: a
Explanation: Apron conveyers are mainly used to perform high end task i.e. at heavy loads and due to its high power consumptions is only used for short runs.
8 - Question
Cyclones are used primarily for separating ____
a) Solid
b) Liquid
c) Solid from liquid
d) Solid from solid
View Answer
Answer: c
Explanation: Cyclones are best utilized for an operation involving solid from liquid, these implies blowing of air through the materials and achieve separation.
9 - Question
Moore filter is a filter_____
a) Leaf
b) Press
c) Rotary
d) Sand
View Answer
Answer: a
Explanation: Moore filter is a leaf filter, the battery of leaves is immersed in a tank of slurry and vacuum is applied through the discharge manifold.
10 - Question
Mesh indicates the number of holes per____
a) Square inch
b) Square foot
c) Linear inch
d) Linear foot
View Answer
Answer: b
Explanation: Mesh is the indication of number of openings per unit area in FPS system, while mesh number is given by linear length.