Engineering Questions with Answers - Multiple Choice Questions

# Environmental Engineering MCQ’s – Racks and Screen

1 - Question

The minimum spacing between the bars on fine screen is ____________
a) 0.3mm
b) 0.9mm
c) 1.5mm
d) 0.5mm

Explanation: The range of space between the bars in fine screen is 1.5-3mm having minimum spacing as 1.5mm.

2 - Question

The spacing between the bars in racks is ____________
a) 30mm
b) 50mm
c) 70mm
d) 90mm

Explanation: The spacing between the bars in racks is 50mm. It is commonly called as coarse screen.

3 - Question

Screens are inclined to the direction of flow to ____________
a) Increase the flow velocity
b) Increase the opening area
c) Decrease the flow velocity

Explanation: Screens are inclined to the direction of flow to decrease the flow velocity in order to increase the efficiency of the screen.

4 - Question

The maximum spacing between the bars in medium screen is ____________
a) 40mm
b) 50mm
c) 70mm
d) 90mm

Explanation: The range of space between the bars in fine screen is 7-40mm having maximum spacing as 40mm.

5 - Question

__________ is used to cut the sewage into smaller parts.
a) Flocculator
b) Tube settlers
c) Shredders
d) Aerators

Explanation: Shredder is a device which is used to cut large size sewage particles into a smaller size. It is composed of screens and cutting teeth.

6 - Question

What is the maximum capacity of medium screen in collecting solids?
a) 30L
b) 40L
c) 50L
d) 90L

Explanation: Medium screen can collect up to the maximum capacity of 90L of solids per 106 L of effluent.

7 - Question

The head loss through the screen is given by HL = k* (Vt2 – Va2), where Vt and Va are velocities through and above the screen respectively. What is the value of constant k?
a) 1
b) 0.0050
c) 0.0729
d) 0.0236