Explore topic-wise MCQs in Mechanical Operations.

This section includes 9 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Operations knowledge and support exam preparation. Choose a topic below to get started.

1.

Which of the following is true about a reverse cyclone used for freeing a fluidized bed of the entrained particles?

A. It consists of an inlet connected axially to the dipleg
B. Outlet tube extends from the bottom of the barrel section
C. Gases exit from the dipleg while the particle leave from outlet tube
D. Centrifugal forces cause gas-solid separation
Answer» E.
2.

Which of the following is not a cause of particle attrition in fluidized beds?

A. When gas jets are placed far
B. When gas jets leaving the distributor intersect
C. High velocity jets cause particles to collide
D. When particle carried by swishing gas flow collide
Answer» B. When gas jets leaving the distributor intersect
3.

Which of the following is the correct equation for pressure drop over orifices when the bed height is greater than 0.3 m?

A. P<sub>orifice</sub> ( frac {1}{3} ) H<sub>bed</sub> ( frac {g}{gc} ) <sub>bulk</sub>
B. P<sub>orifice</sub> ( frac {2}{3} ) H<sub>bed</sub> ( frac {g}{gc} ) <sub>bulk</sub>
C. P<sub>orifice</sub> ( frac {1}{3} ) H<sub>bed</sub> ( frac {g}{gc} ) <sub>bulk</sub>
D. P<sub>orifice</sub> ( frac {2}{3} ) H<sub>bed</sub> ( frac {g}{gc} ) <sub>bulk</sub>
Answer» D. P<sub>orifice</sub> ( frac {2}{3} ) H<sub>bed</sub> ( frac {g}{gc} ) <sub>bulk</sub>
4.

Which of the following characteristic part of a fluidized system is not needed in every system designed?

A. Particle bed region
B. A gas distributor
C. Plenum
D. Heating and cooling coils
Answer» E.
5.

Crush strength of a particle is an indication of the particle s attrition properties which are necessary to study attrition and erosion of the fluidized bed.

A. True
B. False
Answer» C.
6.

Which of the following is true about gas distribution in fluidized beds?

A. Proper gas distribution is independent of the orifice diameters
B. Low grid pressure drop ensures uniform gas distribution
C. Particle weeping can be limited by keeping the pressure drop over orifices above a particular minimum value
D. Ideal pressure drop across a grid plate should be lesser than 4,500 Pa
Answer» D. Ideal pressure drop across a grid plate should be lesser than 4,500 Pa
7.

Fluidized beds cannot be used as dryers.

A. True
B. False
Answer» C.
8.

Which of the following is not a correct characteristic of Fluidized system?

A. Liquid like behavior
B. Cannot resist temperature change
C. Easy control
D. Rapid mixing is also possible
Answer» C. Easy control
9.

Which of the following liquid like properties is correct about fluidized beds?

A. Heavier particles float on the top
B. Have a non-static pressure head
C. Assume the shape of the container that contains it
D. Non zero angle of repose
Answer» D. Non zero angle of repose