Engineering Questions with Answers - Multiple Choice Questions

# Mechanical Operations MCQ’s – Flow

1 - Question

Which of the following velocity components are observed in an agitator?
d) Axial, Inclined, Longitudinal

Explanation: The velocity components observed in agitated tank are radial, axial and longitudinal where each of these components act in a particular direction.

2 - Question

The radial velocity component acts in the direction ____
a) Parallel with the shaft
b) Perpendicular to the shaft
c) Tangent o the circular path around the shaft
d) At an inclined angle with the shaft

Explanation: Radial velocity component always acts in a direction along a radius from the center of the impeller.

3 - Question

The tangential velocity component acts in the direction ____
a) Parallel with the shaft
b) Perpendicular to the shaft
c) Around the shaft
d) At an inclined angle with the shaft

Explanation: The tangential velocity component acts in the tangential direction to the circular motion of the fluid flow.

4 - Question

The axial velocity component acts in the direction ____
a) Parallel with the shaft
b) Perpendicular to the shaft
c) Tangent o the circular path around the shaft
d) At an inclined angle with the shaft

Explanation: Axial velocity component always acts in a direction perpendicular to the radius of the impeller and parallel to the shaft.

5 - Question

When the shaft is vertical and centrally located in the tank, the ____ component is generally disadvantageous.
b) Axial
c) Tangential
d) Rotational

Explanation: The tangential velocity component acts in the tangential direction to the circular motion of the fluid flow around the shaft and creates vortex, which is disadvantageous.

6 - Question

If solid particles are present in agitating tank then instead of mixing reverse concentration may occur.
a) True
b) False

Explanation: When solid particles are present, the circular motion of the impeller tends to throw the particles towards the wall of the tank and from there slide downwards to center of the tank at the bottom.

7 - Question

In small agitating tanks, impellers can be mounted off center in order to prevent swirling.
a) True
b) False

Explanation: In Unbaffled, centrally mounted agitator, circulatory motion of fluids leads to vortex formation. In order to avoid vortex impellers can be mounted off center.

8 - Question

Suspending settling solid particles and low viscosity bulk blending are examples of process that work well utilizing axial flow.
a) True
b) False

Explanation: Agitators that are responsible for axial flow movement are suitable for applications that require high product flow and low turbulent energy, which is beneficial for low viscous fluid.

9 - Question

Which of the following flow is ideal for de-agglomerating solids, dispersion and emulsion?
a) Axial
c) Longitudinal
d) Tangential

Explanation: Radial flow is velocity component acts in a direction along a radius from the center of the impeller which is beneficial for mixing of solid particles, de-agglomerating solids, dispersion, and emulsion.

10 - Question

Axial flow is preferred when solid particles are kept in suspension.
a) True
b) False