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
View Answer
Answer: c
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
View Answer
Answer: b
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
d) Increase the head loss
View Answer
Answer: c
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
View Answer
Answer: a
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
View Answer
Answer: c
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
View Answer
Answer: d
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
View Answer
Answer: c
Explanation: The expression for the head loss through the screen is given by
HL = 0.0729* (Vt2 – Va2), where Vt and Va are the velocities through and above the screen respectively.