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

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

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

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

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

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

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

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

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

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