Engineering Questions with Answers - Multiple Choice Questions
Environmental Engineering MCQ’s – Inverted Siphon, Storm Regulator and Sewage Pumping
1 - Question
Which of the following is called as depressed sewer?
a) Lateral sewer
b) Outfall sewer
c) Inverted siphon
d) Main sewer
View Answer
Answer: c
Explanation: Inverted siphon is also caused as depressed sewer as the pipes between the inlet and the outlet chamber is depressed due to obstruction like roads, bridges etc.
2 - Question
The sewage in inverted siphon will flow under __________
a) Air
b) Vacuum
c) Pressure
d) GravityAnswer: c
Explanation: The sewage in inverted siphon will flow under pressure greater than the atmospheric pressure and it will not flow under gravity.
View Answer
Answer: c
Explanation: The sewage in inverted siphon will flow under pressure greater than the atmospheric pressure and it will not flow under gravity.
3 - Question
The design self cleansing velocity of an inverted siphon is __________
a) 0.9m/Sec
b) 0.6m/Sec
c) 0.7m/Sec
d) 0.4m/Sec
View Answer
Answer: a
Explanation: The design self cleansing velocity of an inverted siphon is 0.9m/Sec for caring minimum, maximum and combined sanitary sewage.
4 - Question
The minimum diameter of an inverted siphon is __________
a) 5cm
b) 10cm
c) 15cm
d) 25cm
View Answer
Answer: c
Explanation: The inverted siphon has a minimum diameter of 15cm and it is made of siphon tubes.
5 - Question
Which sewer appurtenance discharges the excess sewage flow to relief sewer?
a) Flushing tank
b) Drop manhole
c) Lamp hole
d) Storm regulators
View Answer
Answer: d
Explanation: Storm regulators prevents the overloading of sewage treatment plants by discharging the excess sewage flow into relief sewer.
6 - Question
Storm regulators are classified into how many types?
a) 2
b) 3
c) 4
d) 6
View Answer
Answer: b
Explanation: Storm regulator is classified into 3 types, namely Overflow weir, Siphon spillway and Leap weir.
7 - Question
Which of the following is most effective in preventing the overloading of treatment plants?
a) Street inlets
b) Overflow weir
c) Siphon valley
d) Leap weir
View Answer
Answer: b
Explanation: In Siphon valley, the siphonic action takes place when the sewage quantity in combined sewer exceeds the fixed level and it get stopped as soon as it falls below that fixed level.
8 - Question
Which of the following is called a sewage ejector pump?
a) Solid handling pump
b) Air lift pump
c) Diaphragm pump
d) Reciprocating pump
View Answer
Answer: a
Explanation: Solid handling pump is also called as sewage ejector pump where pumping of raw sewage takes place which are mostly in solid form.
9 - Question
Which of the following pump is used for the removal of grit?
a) Centrifugal pump
b) Pneumatic ejector
c) Rotary screw pump
d) Air lift pump
View Answer
Answer: c
Explanation: At Rotary screw pump, the motor rotates on a shaft to lift the solid waste material to a higher level and they are used in grit chambers for removing grit.
10 - Question
The septic tank and pump chamber should be kept as deep as possible.
a) True
b) False
View Answer
Answer: b
Explanation: The septic tank and pump chamber should be placed at shallow depth as it will result in easier inspection, repairment and maintenance of them.
11 - Question
Which part of the pump chamber allows to easily disconnect from the pipeline?
a) Gate valve
b) Check valve
c) Union
d) Pump lift chain
View Answer
Answer: c
Explanation: Union is a device that is placed in the pump discharge pipe that allows the pump to easily disconnect from the pipe in the pump chamber.
12 - Question
Which device warns that the liquid is above the pump level?
a) High level alarm
b) Check valve
c) Union
d) Pump lift chain
View Answer
Answer: a
Explanation: High level alarms give a red light as a warning signal that warns the user that wastewater is above the pump level.
13 - Question
Which of the following device prevents the back flow of wastewater?
a) Gate valve
b) Check valve
c) Union
d) Pump lift chain
View Answer
Answer: b
Explanation: Check valve allows the flow of wastewater in one direction and prevents the back flow of water.
14 - Question
Which component of the pumping chamber prevents ground water from entering the septic tank?
a) Pump lift chain
b) Access riser
c) Check valve
d) Union
View Answer
Answer: b
Explanation: Access riser are large diameter riser with a 61cm diameter that prevents the ground and surface water from entering the septic tank.
15 - Question
Which of the following represents the correct order in terms of the maximum efficiency of the pump?
a) Centrifugal > Airlift > Diaphragm
b) Diaphragm > Airlift > Centrifugal
c) Airlift > Centrifugal > Diaphragm
d) Centrifugal > Diaphragm > Airlift
View Answer
Answer: d
Explanation: The maximum efficiency of the centrifugal pump is 85%, while of Diaphragm and Airlift pumps are 30% and less than 25% respectively.