# Mechanical Operations Questions and Answers – Comparison of Sedimentation and Centrifuge

«
»

This set of Mechanical Operations Questions and Answers for Campus interviews focuses on “Comparison of Sedimentation and Centrifuge”.

1. 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. 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. 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. 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. 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. 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) Kremser

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. 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. 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. 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. Mesh indicates the number of holes per____
a) Square inch
b) Square foot
c) Linear inch
d) Linear foot

Explanation: Mesh is the indication of number of openings per unit area in FPS system, while mesh number is given by linear length.

Sanfoundry Global Education & Learning Series – Mechanical Operations.

To practice all areas of Mechanical Operations for Campus Interviews, here is complete set of 1000+ Multiple Choice Questions and Answers. 