civil engineering MCQs – Page 250

Practise multiple-choice questions from civil engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

civil engineering Mcqs
4981. Ventilating shafts are provided to a sewer line at every__________________?
comments icon0

A. 150 m

B. 100 m

C. 200 m

D. 300 m
4982. A sewer running partially full and hurried with back filled, fails in compression due to_________________?
comments icon0

A. Weight of the back fill

B. All the above

C. Weight of the pipe

D. Superimposed traffic loads

4983. 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?
comments icon0

A. All of these

B. 225 mm dia.

C. 100 mm dia.

D. 150 mm dia.

4984. Hazens formula VS = 418 (GS Gw)d [(3T + 70)/100] is used for the settlement velocity of the particles of diameter______________________?
comments icon0
A. Greater than 0.1 mm

B. Less than 0.01 mm

C. Less than 0.05 mm

D. Less than 0.1 mm

4985. Nitrogen cycle of sewage, is____________________?
comments icon0

A. Liberation of nitrogen-formation of nitrates-formation of nitrites-liberation of ammonia

B. Liberation of nitrogen-liberation of ammonia-formation of nitrites- formation of nitrates

C. Liberation of ammonia-formation of nitrites-formation of nitrates-liberation of nitrogen

D. Formation of nitrates-formation of nitrites-liberation of nitrates-liberation of nitrates

4986. A rainfall may be classified as acidic if its pH value is less or equal to________________?
comments icon0

A. 6

B. 6.5

C. 7

D. 5
4987. Which one of the following statements regarding septic tanks is wrong ?
comments icon0
A. The depth of tank is kept equal to its width

B. The outlet invert level is kept 5 to 7.5 cm below the inlet invert level

C. A gap of 7.5 cm between the bottom of the covering slab and the top level of scum is provided

D. The minimum width of septic level is 90 cm

4988. The most dangerous pollutant in vehicular emissions is____________________?
comments icon0

A. O3

B. CO2

C. SO2

D. CO
4989. If the pH value of sewage is 7__________________?
comments icon0
A. It is neutral

B. It is alkaline

C. It is acidic

D. None of these

4990. pH value of sludge during alkaline regression stage, is__________________?
comments icon0

A. More than 6

B. Less than 6

C. Less than 7

D. More than 7
4991. 3.0 ml of raw sewage is diluted to 300 ml. The D.O. concentration of the diluted sample at the beginning of the test was 8 mg/l. After 5 day-incubation at 20C, the D.O. concentration was 5 mg/l. The BOD of raw sewerage is______________________?
comments icon0
A. 300 mg/l

B. 400 mg/l

C. 200 mg/l

D. 100 mg/l

4992. The gas evolved in sewers is________________?
comments icon0

A. Carbondioxide

B. Hydrogen sulphide

C. Methane

D. All of these
4993. If D is the diameter of a circular sewer and D is the top horizontal diameter of an equivalent egg shaped section, the relationship which holds good, is_______________?
comments icon0

A. D = 0.94 D

B. D = 0.74 D

C. D = 0.64 D

D. D = 0.84 D
4994. The screens are fixed___________________?
comments icon0

A. Parallel to the direction of flow

B. None of these

C. Perpendicular to the direction of flow

D. At an angle 30 to 60 to the direction of flow
4995. House connections to the laterals is generally made by___________________?
comments icon0
A. Glazed stonewares

B. Cast iron

C. R.C.C.

D. P.C.C.

4996. Skimming tanks are__________________?
comments icon0

A. Tanks provided with self- cleansing screens

B. Improved version of grit chambers

C. Used to remove the grease and oil

D. Those from which sludge is skimmed out

4997. If the side of a square sewer is 1000 mm, the diameter of a hydraulically equivalent circular section, is___________________?
comments icon0

A. 1065 mm

B. 1095 mm

C. 1075 mm

D. 1045 mm

4998. The sewerage system consists of______________________?
comments icon0
A. All of these

B. Branch sewer

C. House sewer

D. Lateral sewer

4999. The disintegrating pump in which solid matter is broken up before passing out, is__________________?
comments icon0

A. Pneumatic ejector

B. None of these

C. Reciprocating pump

D. Centrifugal pump
5000. In sewers the gas generally found, is_________________?
comments icon0
A. All the above

B. Hydrogen sulphide (H2S)

C. Carbon dioxide (CO2)

D. Methane (CH4)