Engineering Questions with Answers - Multiple Choice Questions

Environmental Engineering MCQ – 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

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




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.

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