Explore topic-wise MCQs in Civil Engineering.

This section includes 260 Mcqs, each offering curated multiple-choice questions to sharpen your Civil Engineering knowledge and support exam preparation. Choose a topic below to get started.

1.

The ratio of minimum hourly flow to the average flow of sewage is%!

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

The minimum diameter of a sewer is kept%!

A. 10 cm
B. 15 cm
C. 20 cm
D. 25 cm
Answer» C. 20 cm
3.

For a peak discharge of 0.0157 cumec, with a velocity of 0.9 m/sec, the diameter of the sewer main, is%!

A. 10 cm
B. 12 cm
C. 15 cm
D. 18 cm
Answer» D. 18 cm
4.

The self-cleansing velocity of water flowing through pipe lines, is%!

A. 2 metres/sec
B. 1 metre/sec
C. 0.5 metre/sec
D. 0.25 metre/sec
Answer» B. 1 metre/sec
5.

The detention time of a circular tank of diameter d and water depth H, for receiving the sewage Q per hour, is%!

A. d² (0.011d + 0.785H)/Q
B. d (0.022d + 0.085H)/Q
C. d (0.785d + 0.011H)/Q
D. d (0.285d + 0.011H)/Q
Answer» B. d (0.022d + 0.085H)/Q
6.

A manhole is generally provided at each%!

A. Bend
B. Junction
C. Change of gradient
D. All the above
Answer» E.
7.

For laying a sewer line in a trench of 2 m width, an offset line is marked on the ground parallel to the given centre line at a distance of%!

A. 100 cm
B. 120 cm
C. 140 cm
D. 160 cm
Answer» E.
8.

The spacing of man holes along a straight portion of a sewer is 300 m, the diameter of the sewer may be%!

A. 0.9 cm
B. 1.2 m
C. 1.5 m
D. > 1.5 m
Answer» E.
9.

In a trickling filter%!

A. Filtration process is used
B. Biological action is used
C. Neither A nor B
D. Both A and B
Answer» C. Neither A nor B
10.

The pH value of sewage is determined with the help of%!

A. Imhoff Cone
B. Turbid meter
C. Potentiometer
D. None of these
Answer» D. None of these
11.

A manhole is classified as shallow if its depth is between%!

A. 0.4 to 0.5 m
B. 0.5 to 0.7 m
C. 0.7 to 0.9 m
D. 0.9 to 1.20 m
Answer» D. 0.9 to 1.20 m
12.

The recommended detention period for grit chambers is%!

A. 1 minute
B. 2 minutes
C. 3 minutes
D. 5 minutes
Answer» B. 2 minutes
13.

Flocculated particles do not change their%!

A. Size
B. Shape
C. Weight
D. None of these
Answer» E.
14.

If the depletion of oxygen is found to be 2.5 mg/litre after incubating 2.5 ml of sewage diluted to 250 ml for 5 days at 20°C, B.O.D. of the sewage is%!

A. 50 mg/l
B. 100 mg/l
C. 150 mg/l
D. 250 mg/l
Answer» E.
15.

*$_Ventilating shafts are provided to a sewer line at every?

A. 100 m
B. 150 m
C. 200 m
D. 300 m
Answer» E.
16.

*$_The average temperature of sewage in India, is?

A. 10°C
B. 15°C
C. 20°C
D. 25°C
Answer» D. 25¬¨‚àûC
17.

*$_The sewerage system consists of?

A. House sewer
B. Lateral sewer
C. Branch sewer
D. All of these
Answer» E.
18.

*$_The sewer which received discharge from two or more main sewers, is known as?

A. A trunk sewer
B. An outfall sewer
C. A main sewer
D. An intercepting sewer
Answer» B. An outfall sewer
19.

*$_The sewer which collects the discharge from a collecting system and delivers it to a treatment plant, is known?

A. House sewer
B. Lateral sewer
C. Branch sewer
D. Sewer outfall
Answer» E.
20.

*$_If the diameter of sewer is 225 mm, the gradient required for generating self cleansing velocity, is?

A. 1 in 60
B. 1 in 100
C. 1 in 120
D. None of these
Answer» D. None of these
21.

*$_The normal value of over flow rates for plain primary sedimentation tanks, ranges between?

A. 25,000 to 35,000 litres/sqm/day
B. 40,000 to 50,000 litres/sqm/day
C. 50,000 to 60,000 litres/sqm/day
D. 80,000 to 100,000 litres/sqm/day
Answer» C. 50,000 to 60,000 litres/sqm/day
22.

*$_To maintain aerobic biological activity, the moisture content of the compost mass should be about?

A. 45 %
B. 50 %
C. 55 %
D. 60 %
Answer» D. 60 %
23.

*$_The small sewers are cleaned by?

A. Flushing
B. Cane rodding
C. Wooden pills
D. None of these
Answer» B. Cane rodding
24.

*$_The settling velocity of a spherical particle of diameter less than 0.1 mm as per Stock’s law, is?

A. Vs = 418 (Gs – Gw) d [(3T + 70)/100]
B. Vs = 418 (Gs – Gw)d² [(3T + 70)/100]
C. Vs = 218 (Gs – Gw)d² [(3T + 70)/100]
D. Vs = 218 (Gs – Gw)d [(3T + 70)/100]
Answer» C. Vs = 218 (Gs ‚Äö√Ñ√¨ Gw)d¬¨‚â§ [(3T + 70)/100]
25.

*$_The density of population over 40 hectares is 250/hectare. If water supply demand per day is 200 litres and sewage discharge is 80% of water supply, the sewage flow in sewers of separate system, is?

A. 0.05552 cumec
B. 0.05554 cumec
C. 0.05556 cumec
D. 0.0556 cumec
Answer» D. 0.0556 cumec
26.

*$_The detention time (t) of a settling tank, may be defined as the time required for?

A. A particle to travel along its length
B. A particle to travel from top surface to bottom sludge zone
C. The flow of sewage to fill the tank
D. None of these
Answer» D. None of these
27.

*$_During preliminary treatment of a sewage?

A. Oil and grease are removed from skimming tanks
B. Floating materials are removed by screening
C. Girt and sand are removed by girt chambers
D. All the above
Answer» E.
28.

*$_The minimum recommended diameter of sewers, is?

A. 5 cm
B. 10 cm
C. 15 cm
D. 20 cm
Answer» D. 20 cm
29.

*$_depends upon The Chezy’s constant C in the formula V = C?

A. Size of the sewer
B. Shape of the sewer
C. Roughness of sewer surface
D. All the above
Answer» E.
30.

*$_If the pH value of sewage is 7?

A. It is acidic
B. It is alkaline
C. It is neutral
D. None of these
Answer» D. None of these
31.

*$_For sewers, inverted siphon is provided for?

A. One pipe
B. Two pipes
C. Three pipes
D. Four pipes
Answer» D. Four pipes
32.

*$_The formula which accepts the value of rugosity coefficient n = 0.012 to be used in Manning’s formula, is given by?

A. Bazin
B. Crimp and Bruges
C. William-Hazen
D. Kutter
Answer» C. William-Hazen
33.

*$_The non-clog pump which permits solid matter to pass out with the liquid sewage, is?

A. Centrifugal pump
B. Reciprocating pump
C. Pneumatic ejector
D. None of these
Answer» B. Reciprocating pump
34.

*$_In sewers the velocity of flow should not be?

A. More than the self-cleansing velocity
B. Less than the self-cleansing velocity
C. Less than 10 m/sec
D. More than 20 m/sec
Answer» C. Less than 10 m/sec
35.

*$_The rate of accumulation of sludge in septic tanks is recommended as?

A. 30 litres/person/year
B. 25 litres/person/year
C. 30 litres/person/month
D. 25 litres/person/month
Answer» B. 25 litres/person/year
36.

*$_Skimming tanks are?

A. Used to remove the grease and oil
B. Those from which sludge is skimmed out
C. Tanks provided with self- cleansing screens
D. Improved version of grit chambers
Answer» B. Those from which sludge is skimmed out
37.

*$_Which one of the following part of human body withstands minimum radiation??

A. Thyroid
B. Kidneys
C. Eyes
D. Ovaries/testis
Answer» E.
38.

*$_Chlorination of water is done for the removal of?

A. Bacterias
B. Suspended solids
C. Sediments
D. Hardness
Answer» B. Suspended solids
39.

*$_The most effective arrangement for diverting excess storm water into a natural drainage, is?

A. Leaping weir
B. Overflow weir
C. Siphon spill way
D. None of these
Answer» D. None of these
40.

*$_The width of a settling tank with 2 hour detention period for treating sewage 378 cu m per hour, is?

A. 5 m
B. 5.5 m
C. 6.5 m
D. 7 m
Answer» E.
41.

*$_The sewer which resists sulphide corrosion, is?

A. Brick sewer
B. Cast iron sewer
C. R.C. sewer
D. Lead sewer
Answer» E.
42.

*$_For laying a sewer line in a trench of 2 m width, an offset line is marked on the ground parallel to the given centre line at a distance of?

A. 100 cm
B. 120 cm
C. 140 cm
D. 160 cm
Answer» E.
43.

*/*_The ratio of minimum hourly flow to the average flow of sewage is?

A. 1/4
B. 1/3
C. 1/2
D. 3/4
Answer» C. 1/2
44.

*/*_The detention time of a circular tank of diameter d and water depth H, for receiving the sewage Q per hour, is?

A. d² (0.011d + 0.785H)/Q
B. d (0.022d + 0.085H)/Q
C. d (0.785d + 0.011H)/Q
D. d (0.285d + 0.011H)/Q
Answer» B. d (0.022d + 0.085H)/Q
45.

*/*_The minimum diameter of a sewer is kept?

A. 10 cm
B. 15 cm
C. 20 cm
D. 25 cm
Answer» C. 20 cm
46.

*/*_The self-cleansing velocity of water flowing through pipe lines, is?

A. 2 metres/sec
B. 1 metre/sec
C. 0.5 metre/sec
D. 0.25 metre/sec
Answer» B. 1 metre/sec
47.

*/*_For a peak discharge of 0.0157 cumec, with a velocity of 0.9 m/sec, the diameter of the sewer main, is?

A. 10 cm
B. 12 cm
C. 15 cm
D. 18 cm
Answer» D. 18 cm
48.

*/*_Inter-distance between ventilation columns in a sewer line is kept?

A. 25 to 50 m
B. 50 m to 100 m
C. 100 m to 150 m
D. 150 m to 300 m
Answer» E.
49.

*/*_If the flame of a miner's safety lamp in the upper layers of the sewer forms an explosive, the sewer certainly contains?

A. Hydrogen sulphide
B. Carbon dioxide
C. Methane
D. Oxygen
Answer» D. Oxygen
50.

*/*_For trunk and out-fall, the type of sewers generally used, is?

A. Standard egg shaped
B. Circular shaped
C. Horse shoe shaped
D. Parabolic shaped
Answer» D. Parabolic shaped