Explore topic-wise MCQs in Civil Engineering.

This section includes 641 Mcqs, each offering curated multiple-choice questions to sharpen your Civil Engineering knowledge and support exam preparation. Choose a topic below to get started.

601.

In a residential colony, sewers of diameters 100 mm, 150 mm and 225 mm were laid with a gradient 1 in 120. Which portion of the sewage system does not choke in due course of time

A. 100 mm dia.
B. 150 mm dia.
C. 225 mm dia.
D. all of these.
Answer» D. all of these.
602.

For the COD test of sewage, organic matter is oxidised by K2Cr207 in the presence of

A. H2SO4
B. HNO3
C. HCl
D. none of these.
Answer» B. HNO3
603.

The underground sewers are more subjected to

A. tensile force
B. compressive force
C. bending force
D. shearing force.
Answer» C. bending force
604.

D is the diameter of a circular sewer and α is the side of a square section sewer. If both are hydraulically equivalent, the relationship which holds good, is

A. πD8/3 = 4 b8/3
B. πD3/8 = 4 b3/8
C. πD2/3 = 4 b2/3
D. πD3/2 = 4 b3/2
Answer» B. œÄD3/8 = 4 b3/8
605.

For estimating the peak run off the rational formula Q = 0.0278 KpA was evolved by

A. Kinchling
B. Lloyd Davis
C. Frubling
D. all the above.
Answer» E.
606.

In septic tanks, decomposition of organic bacteria, is done by

A. anaerobic bacteria
B. aerobic bacteria
C. both types of bacterias
D. none of these.
Answer» B. aerobic bacteria
607.

In a fully mechanised composting plant, involves

A. mechanized receipt
B. mechanized segregation
C. mechanized pulverising of refuse
D. all of these.
Answer» E.
608.

In olden days the type of section adopted in trunk and out fall sewers was

A. parabolic shaped
B. horse shoe shaped
C. egg shaped
D. circular shaped.
Answer» C. egg shaped
609.

In 1000 kg of sewage, the total solids approximate

A. 0.5 to 1.0 kg
B. 1 kg to 2.0 kg
C. 5 kg to 7.5 kg
D. 7.5 kg to 10 kg.
Answer» B. 1 kg to 2.0 kg
610.

A rainfall may be classified as acidic if its pH value is less or equal to

A. 6
B. 7
C. 5
D. 6.5
Answer» D. 6.5
611.

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 Bruge
C. William-Hazen
D. Kutter.
Answer» C. William-Hazen
612.

If the peak discharge of a storm water drain (S.W. Drain) is e.xpected to exceed 150 cumecs, the free board to be provided, is

A. 100 cm
B. 90 cm
C. 80 cm
D. 50 cm.
Answer» B. 90 cm
613.

The ratio of design discharge to the surface area of a sedimentation tank is called

A. surface loading
B. overflow rate
C. overflow velocity
D. all of these.
Answer» E.
614.

In sewers the highest non-scouring velocity is achieved in

A. glazed bricks sewers
B. cast iron sewers
C. cement concrete sewers
D. stone ware sewers.
Answer» B. cast iron sewers
615.

For sewers, inverted siphon is provided for

A. one pipe
B. two pipes
C. three pipes
D. four pipes.
Answer» D. four pipes.
616.

The rainfall at any place may be determined by

A. its intensity
B. its direction
C. its frequency
D. all the above.
Answer» E.
617.

The gas which may cause explosion in sewers, is

A. carbondioxide
B. methane
C. ammonia
D. carbon monoxide.
Answer» C. ammonia
618.

The intensity of rain is expressed in

A. cm/minute
B. cm/hour
C. cm/day
D. none of these.
Answer» C. cm/day
619.

Rate of flow of sewage is generally assumed

A. more than the rate of water supply
B. equal to the rate of water supply
C. less than the rate of water supply
D. at 150 litres per capita.
Answer» D. at 150 litres per capita.
620.

In SI units the power of sound is represented in

A. kgs
B. joules
C. neutons
D. watts.
Answer» E.
621.

Drop manholes at the junctions of sewer lines, are provided if

A. invert level of a branch sewer is more than 60 cm that of the main sewer
B. sewer line runs along a main road
C. ordinary manhole cannot be built
D. two sewer lines intersect.
Answer» B. sewer line runs along a main road
622.

Chlorination of water is done for the removal of

A. bacterias
B. suspended solids
C. sediments
D. hardness.
Answer» B. suspended solids
623.

The ratio of the diameter of a circular section and the side of a square section hydraulically equivalent, is

A. 1.095
B. 1.085
C. 1.075
D. 1.065
Answer» B. 1.085
624.

Aerobic bacterias

A. flourish in the presence of free oxygen
B. consume organic matter as their food
C. oxidise organic matter in sewage
D. All the above.
Answer» E.
625.

The asbestos cement pipes are generally laid

A. horizontally
B. vertically
C. at an angle of 30°
D. at an angle of 60°.
Answer» C. at an angle of 30¬∞
626.

The pH value of fresh sewage is usually

A. equal to 7
B. more than 7
C. less than 7
D. equal to zero.
Answer» C. less than 7
627.

If the over land flow from the critical point to the drain is 8 km and the difference in level is 12.4 m, the inlet time is

A. 2 hours
B. 3 hours
C. 4 hours
D. 5 hours.
Answer» D. 5 hours.
628.

Sewer pipes need be checked for

A. minimum flow
B. maximum flow
C. both (a) and (b)
D. none of these.
Answer» D. none of these.
629.

Flocculated particles do not change their

A. size
B. shape
C. weight
D. none of these.
Answer» E.
630.

To maintain aerobic biological activity, the moisture content of the compost mass should be about

A. 0.45
B. 0.5
C. 0.55
D. 60%.
Answer» D. 60%.
631.

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
632.

The sewage is pumped up

A. from low lying areas
B. from flat areas
C. from basements
D. across a high ridge
Answer» E.
633.

The most dangerous pollutant in vehicular emissions is

A. CO
B. SO2
C. CO2
D. O3.
Answer» B. SO2
634.

Dilution method of disposing off sewage, is not preferred to

A. when sewage is fresh
B. when diluting water has high dissolved oxygen content
C. when diluting water is used for water supply near the point of sewage disposed
D. when the diluting water is having flow currents
Answer» D. when the diluting water is having flow currents
635.

If 2% solution of a sewage sample is incubated for 5 days at 20°C and depletion of oxygen was found to be 5 ppm, B.O.D. of the sewage is

A. 200 ppm
B. 225 ppm
C. 250 ppm
D. None of these.
Answer» D. None of these.
636.

If D is the diameter of upper circular portion, the overall depth of a standard egg shaped section, is

A. D
B. 1.25 D
C. 1.5 D
D. 1.75 D
Answer» D. 1.75 D
637.

A nuisance is experienced in diluting water if dilution factor is less than

A. 100
B. 60
C. 40
D. 20
Answer» E.
638.

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.
639.

Clogging of sewers, is caused due to

A. silting
B. low discharge
C. greasy and oily matters
D. domestic wastes thrown in manholes
Answer» E.
640.

In areas where light rains are uniformly distributed throughout the year, the type of sewerage system to be adopted is

A. separate system
B. combined system
C. partially combined system
D. none of these.
Answer» C. partially combined system
641.

The minimum recommended diameter of sewers, is

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