Engineering Questions with Answers - Multiple Choice Questions
Environmental Engineering MCQ’s – Dry Weather Flow
1 - Question
________ is the flow through sewers available during non-rainfall period.
a) Gradually varied flow
b) Rapidly varied flow
c) Dry weather flow
d) Storm water flow
View Answer
Answer: c
Explanation: Dry weather flow is the flow through sewers available during non-rainfall period. It consists of domestic sewage and waste water sewage.
2 - Question
_______ is the additional flow occurring during rainy season.
a) Gradually varied flow
b) Rapidly varied flow
c) Dry weather flow
d) Storm water flow
View Answer
Answer: d
Explanation: The storm water flow is the additional flow occurring during the rainy season. It consists of runoff from roofs, streets or open spaces during rainfall.
3 - Question
Which flow is also called as sanitary sewage?
a) Dry weather flow
b) Storm weather flow
c) Uniform flow
d) Non uniform flow
View Answer
Answer: a
Explanation: Dry weather flow is the quantity of wastewater that flows through a sewer in dry weather when no storm water is present in the sewer.
4 - Question
Which of the following factor does not effect the dry weather flow?
a) Rate of water supply
b) Temperature conditions
c) Population growth
d) Infiltration of ground water
View Answer
Answer: b
Explanation: There are four factors that affect the dry weather flow, namely the rate of water supply, population growth, type of area served and infiltration of ground water.
5 - Question
The quantity of waste water is assumed to be ___________ % of the quantity of water supply.
a) 40
b) 50
c) 60
d) 80
View Answer
Answer: d
Explanation: The quantity of waste water is assumed to be 80 % of the quantity of water supply when no extra water enters the sewer.
6 - Question
The sewer should be designed for a minimum of ______ litres of waste water per capita per day.
a) 50
b) 100
c) 150
d) 1000
View Answer
Answer: c
Explanation: Sewer is an underground carriage system that takes impure water from houses and commercial buildings through pipes to treatment units and they should be designed for a minimum of 150 litres of waste water per capita per day.
7 - Question
The size of the town is 15,000. What is the density of population per hectare?
a) 50
b) 75
c) 100
d) 200
View Answer
Answer: d
Explanation: When the size of the town is between 5000 and 20,000, the density of population per hectare is between 150 and 200.
8 - Question
The design period of main and branch sewer is ___________
a) 5years
b) 10years
c) 30years
d) 40years
View Answer
Answer: c
Explanation: The main and branch sewer is designed for the population that may occur at the end of one generation of 30 years.This period of 30 years is called a design period.
9 - Question
________ is the process in which ground water unfiltrate into the sewers.
a) Exfiltration
b) Infiltration
c) Filtration
d) Osmosis
View Answer
Answer: b
Explanation: Infiltration is the process in which ground water unfiltrate into the sewers. It increases the load on the treatment work.
10 - Question
________ is the process which indicates the flow of waste water from the sewer into the ground.
a) Exfiltration
b) Infiltration
c) Filtration
d) Osmosis
View Answer
Answer: a
Explanation: Exfiltration is the reverse process of Infiltration where flow through sewer decreases and pollution of the ground water increases.
11 - Question
Infiltration of water does not depend on ___________
a) Size of sewer
b) Sewer material
c) Quality of water
d) Type of soil
View Answer
Answer: c
Explanation: The infiltration of water depends on depth of sewer below ground water, size and length of sewer, sewer material, type of joints, nature and type of soil through which sewer is laid.
12 - Question
The rate of infiltration lies in the range of ______ m3/hectare/day.
a) 0.20-0.28
b) 0.42-0.63
c) 0.60-0.80
d) 0.70-0.90
View Answer
Answer: a
Explanation: The rate of infiltration is expressed as litres per hectare of area per day. The rate of infiltration lies in the range of 0.2-0.28m3/hectare/day.
13 - Question
The relation between the maximum and average rate of flow is defined by ___________
a) QMAX = (1 + 14/(4 + P0.5)) * QAVG
b) QMAX = (1 + 1/(4 + P0.5)) * QAVG
c) QMAX = (1 + 4 + P0.5) * QAVG
d) QMAX = (1 + P0.5) * QAVG
View Answer
Answer: a
Explanation: According to Harmon’s formula, the maximum and the average rate of flow is defined by QMAX = (1 + 14/(4 + P0.5)) * QAVG where P is the population in thousands.