Explore topic-wise MCQs in Civil Engineering.

This section includes 167 Mcqs, each offering curated multiple-choice questions to sharpen your Civil Engineering knowledge and support exam preparation. Choose a topic below to get started.

101.

The settling velocity of a particle in a sedimentation tank increases if$?

A. Particle size is decreased
B. The surface area of tank is increased
C. The depth of tank is decreased
D. None of the above
Answer» E.
102.

The design discharge for the separate sewer system shall be taken as$?

A. Equal to dry weather flow (DWF)
B. 2 √ó DWF
C. 3 √ó DWF
D. 6 √ó DWF
Answer» E.
103.

Which of the following unit works in anaerobic conditions?$?

A. Sludge digestion tank
B. Sedimentation tank
C. Activated sludge treatment
D. Trickling filters
Answer» B. Sedimentation tank
104.

The type of valve, which is provided on the suction pipe in a tube-well, is$?

A. Air relief valve
B. Reflux valve
C. Pressure relief valve
D. Sluice valve
Answer» C. Pressure relief valve
105.

Scour valves are provided$?

A. At street corners to control the flow of water
B. At every depression and dead ends to drain out the waste water that may collect there
C. At the foot of rising main along the slope to prevent back running of water
D. At every summit of rising mains
Answer» C. At the foot of rising main along the slope to prevent back running of water
106.

The relative stability of a sewage sample, whose dissolved oxygen is same as the total oxygen required to satisfy BOD, is$?

A. 1
B. 100
C. Infinite
D. Zero
Answer» C. Infinite
107.

Average rate of water consumption per head per day as per Indian Standard is$?

A. 100 liters
B. 135 liters
C. 165 liters
D. 200 liters
Answer» C. 165 liters
108.

The treatment of water with bleaching powder is known as$?

A. Pre-chlorination
B. Super chlorination
C. De-chlorination
D. Hypo-chlorination
Answer» E.
109.

The overflow rate for plain sedimentation tanks is about$?

A. 500 to 750 liters/hour/ m²
B. 1000 to 1250 liters/hour/ m²
C. 1250 to 1500 liters/hour/m²
D. 1500 to 2000 liters/hour/m²
Answer» B. 1000 to 1250 liters/hour/ m¬¨‚â§
110.

Alum as a coagulant is found to be most effective when pH range of water is$?

A. 2 to 4
B. 4 to 6
C. 6 to 8
D. 8 to 10
Answer» D. 8 to 10
111.

The type of valve which is provided to control the flow of water in the distribution system at street corners and where the pipe lines intersect is

A. Check valve
B. Sluice valve
C. Safety valve
D. Scour valve
Answer» C. Safety valve
112.

The specific gravity of sewage is

A. Much greater than 1
B. Slightly less than 1
C. Equal to 1
D. Slightly greater than 1
Answer» E.
113.

Period of cleaning of slow sand filters is about

A. 24 - 48 hours
B. 10 - 12 days
C. 2 - 3 months
D. 1 - 2 year
Answer» D. 1 - 2 year
114.

The distribution mains are designed for

A. Maximum daily demand
B. Maximum hourly demand
C. Average daily demand
D. Maximum hourly demand on maximum day
Answer» E.
115.

Generally the detention period for grit chambers is kept as

A. 1 minute
B. 5 minutes
C. 24 hours
D. 12 hours
Answer» B. 5 minutes
116.

Which of the following retards the self purification of stream?

A. Higher temperature
B. Sunlight
C. Satisfying oxygen demand
D. None of the above
Answer» E.
117.

As compared to shallow wells, deep wells have

A. More depth
B. Less depth
C. More discharge
D. Less discharge
Answer» D. Less discharge
118.

The maximum efficiency of BOD removal is achieved in

A. Oxidation pond
B. Oxidation ditch
C. Aerated lagoons
D. Trickling filters
Answer» C. Aerated lagoons
119.

The characteristics of fresh and septic sewage respectively are

A. Acidic and alkaline
B. Alkaline and acidic
C. Both acidic
D. Both alkaline
Answer» C. Both acidic
120.

The hourly variation factor is usually taken as

A. 1.5
B. 1.8
C. 2.0
D. 2.7
Answer» B. 1.8
121.

The maximum permissible limit for fluoride in drinking water is

A. 0.1 mg/liter
B. 1.5 mg/liter
C. 5 mg/liter
D. 10 mg/liter
Answer» C. 5 mg/liter
122.

The most common cause of acidity in water is

A. Carbon dioxide
B. Oxygen
C. Hydrogen
D. Nitrogen
Answer» B. Oxygen
123.

The percentage of chlorine in fresh bleaching powder is about

A. 10 to 15
B. 20 to 25
C. 30 to 35
D. 40 to 50
Answer» D. 40 to 50
124.

The type of valve which allows water to flow in one direction but prevents its flow in the reverse direction is

A. Reflux valve
B. Sluice valve
C. Air relief valve
D. Pressure relief valve
Answer» B. Sluice valve
125.

The rate of BOD exerted at any time is

A. Directly proportional to BOD satisfied
B. Directly proportional to BOD remaining
C. Inversely proportional to BOD satisfied
D. Inversely proportional to BOD remaining
Answer» C. Inversely proportional to BOD satisfied
126.

Residual chlorine in water is determined by

A. Starch iodide method
B. Orthotolidine method
C. Both (A) and (B)
D. None of the above
Answer» D. None of the above
127.

The velocity of flow of water in a sedimentation tank is about

A. 5 to 10 cm/sec
B. 15 to 30 cm/sec
C. 15 to 30 cm/minute
D. 15 to 30 cm/hour
Answer» D. 15 to 30 cm/hour
128.

On standard silica scale, the turbidity in drinking water should be limited to

A. 10 ppm
B. 20 ppm
C. 30 ppm
D. 50 ppm
Answer» B. 20 ppm
129.

The hydraulic mean depth (HMD) for an egg-shaped sewer flowing two-third full is

A. Equal to HMD when flowing full
B. Less than HMD when flowing full
C. Greater than HMD when flowing full
D. None of the above
Answer» D. None of the above
130.

Which of the following sewers is preferred for combined system of sewage?

A. Circular sewer
B. Egg shaped sewer
C. Rectangular sewer
D. None of the above
Answer» C. Rectangular sewer
131.

If the sewage contains grease and fatty oils, these are removed in

A. Grit chambers
B. Detritus tanks
C. Skimming tanks
D. Sedimentation tanks
Answer» D. Sedimentation tanks
132.

Alkalinity in water is expressed as milligrams per litre in terms of equivalent

A. Calcium carbonate
B. Magnesium carbonate
C. Sodium carbonate
D. Calcium hydroxide
Answer» B. Magnesium carbonate
133.

The ratio of 5 day BOD to ultimate BOD is about

A. 1/3
B. 2/3
C. 3/4
D. 1.0
Answer» C. 3/4
134.

In lime-soda process

A. Only carbonate hardness is removed
B. Only noncarbonated hardness is removed
C. Lime reduces the carbonate hardness and soda-ash removes the non-carbonate hardness
D. Lime reduces the non-carbonate hardness and soda-ash removes the carbonate hardness
Answer» D. Lime reduces the non-carbonate hardness and soda-ash removes the carbonate hardness
135.

For the same solid content, if the quantity of sludge with moisture content of 98% is X, then the quantity of sludge with moisture content of 96% will be

A. X/4
B. X/2
C. X
D. 2X
Answer» C. X
136.

The suitable method of forecasting population for a young and rapidly increasing city is

A. Arithmetical increase method
B. Geometrical increase method
C. Incremental increase method
D. Graphical method
Answer» C. Incremental increase method
137.

The devices which are installed for drawing water from the sources are called

A. Aquifers
B. Aquiclude
C. Filters
D. Intakes
Answer» E.
138.

The slope of sewer shall be

A. Given in the direction of natural slope of ground
B. Given in the direction opposite to natural slope of ground
C. Zero
D. Steeper than 1 in 20
Answer» B. Given in the direction opposite to natural slope of ground
139.

The process in which the chlorination is done beyond the break point is known as

A. Pre-chlorination
B. Post chlorination
C. Super chlorination
D. Break point chlorination
Answer» D. Break point chlorination
140.

Which of the following chemical compounds can be used for de-chlorination of water?

A. Carbon dioxide
B. Bleaching powder
C. Sulphur dioxide
D. Chloramines
Answer» D. Chloramines
141.

If Biochemical oxygen demand (BOD) of a town is 20000 kg/day and BOD per capita per day is 0.05 kg, then population equivalent of town is

A. 1000
B. 4000
C. 1,00,000
D. 4,00,000
Answer» E.
142.

Orthotolidine test is used for determination of

A. Dissolved oxygen
B. Residual chlorine
C. Biochemical oxygen demand
D. Dose of coagulant
Answer» C. Biochemical oxygen demand
143.

Which of the following values of pH represents a stronger acid?

A. 2
B. 5
C. 7
D. 10
Answer» B. 5
144.

Sewage treatment units are normally designed for

A. 5 - 10 years
B. 15 - 20 years
C. 30 - 40 years
D. 40 - 50 years
Answer» C. 30 - 40 years
145.

The amount of residual chlorine left in public water supply for safety against pathogenic bacteria is about

A. 0.01 to 0.05 ppm
B. 0.05 to 0.5 ppm
C. 0.5 to 1.0 ppm
D. 1.0 to 5.0 ppm
Answer» C. 0.5 to 1.0 ppm
146.

The correct relation between theoretical oxygen demand (TOD), Biochemical oxygen demand (BOD) and Chemical oxygen demand (COD) is given by

A. TOD > BOD > COD
B. TOD > COD > BOD
C. BOD > COD > TOD
D. COD > BOD > TOD
Answer» C. BOD > COD > TOD
147.

The gas from sludge digestion tank is mainly composed of

A. Nitrogen
B. Carbon dioxide
C. Hydrogen sulphide
D. Methane
Answer» E.
148.

In chlorination, with the rise in temperature of water, death rate of bacteria

A. Increases
B. Decreases
C. Remains unaffected
D. None of the above
Answer» B. Decreases
149.

Standard EDTA (ethylene diamine tetra acetic acid) solution is used to determine the

A. Hardness in water
B. Turbidity in water
C. Dissolved oxygen in water
D. Residual chlorine in water
Answer» B. Turbidity in water
150.

Sludge volume index is defined as the ratio of

A. Percentage of sludge by volume to percentage of suspended solids by weight
B. Percentage of sludge by volume to percentage of total solids by weight
C. Percentage of suspended solids by weight to percentage of sludge by volume
D. Percentage of total solids by weight to percentage of sludge by volume
Answer» B. Percentage of sludge by volume to percentage of total solids by weight