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.

351.

Kjeldahl nitrogen is a mixture of

A. mmonia and nitrogen
B. itrogen and organic nitrogen
C. rganic nitrogen and ammonia
D. ll the above
Answer» E.
352.

¾th or ¼th extra space is left in sewer pipes at maximum discharge for

A. ow estimates of the average and maximum flows
B. arge scale infiltration of storm water
C. nexpected increase in population
D. ll the above
Answer» E.
353.

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

A. azin
B. rimp and Bruges
C. illiam-Hazen
D. utter
Answer» C. illiam-Hazen
354.

In sewers the velocity of flow should not be

A. ore than the self-cleansing velocity
B. ess than the self-cleansing velocity
C. ess than 10 m/sec
D. ore than 20 m/sec
Answer» C. ess than 10 m/sec
355.

Cement concrete sewers are only suitable if non-scouring velocity is between

A. .5 to 3.0 m/sec
B. .0 to 4.0 m/sec
C. .5 to 4.5 m/sec
D. .5 to 5.5 m/sec
Answer» B. .0 to 4.0 m/sec
356.

Sludge banks are formed if sewage is disposed of in

A. ivers
B. eas
C. akes
D. one of these
Answer» C. akes
357.

A five day B.O.D. at 15°C of the sewage of a town is 100 kg/day. If the 5 day B.O.D. per head at 15°C for standard sewage is 0.1 kg/day, the population equivalent is

A. 00
B. 000
C. 000
D. 0000
Answer» E.
358.

A drop manhole is provided if

A. sewer drops from a height
B. branch sewer joins the main sewer at higher level
C. lamp is inserted to check obstruction
D. one of these
Answer» C. lamp is inserted to check obstruction
359.

The formula V = (1/n) r2/3

A. hezy’s formula
B. azin’s formula
C. utter’s formula
D. anning’s formula
Answer» E.
360.

‘Cowl’ is provided at

A. ower end of ventilating column
B. pper end of ventilating column
C. pper end of the manhole
D. irst step in manhole
Answer» C. pper end of the manhole
361.

Which one of the following part of human body withstands minimum radiation?

A. hyroid
B. idneys
C. yes
D. varies/testis
Answer» E.
362.

If the diameter of a sewer is 100 mm, the gradient required for generating self cleansing velocity is

A. in 60
B. in 100
C. in 120
D. one of these
Answer» B. in 100
363.

Pathogens (or pathogenic bacterias) in water may cause

A. yphoid
B. holera
C. ysentery
D. ll the above
Answer» E.
364.

To test chemical oxygen demand (C.O.D.) of sewage, organic matter is oxidised by potassium dichromate in the presence of

A. ydrochloric acid
B. ulphuric acid
C. itric acid
D. itric acid
Answer» C. itric acid
365.

For the COD test of sewage, organic matter is oxidised by K₂Cr₂O₇ in the presence of

A. ₂SO₄
B. NO₃
C. Cl
D. one of these
Answer» B. NO₃
366.

Hazen’s formula VS = 418 (GS – Gw)d [(3T + 70)/100] is used for the settlement velocity of the particles of diameter

A. ess than 0.01 mm
B. ess than 0.05 mm
C. ess than 0.1 mm
D. reater than 0.1 mm
Answer» E.
367.

In Chezy’s formula V = C rs for calculating the velocity of flow in circular sewer of diameter running full, the value of hydraulic mean radius is

A. /1
B. /2
C. /3
D. /4
Answer» E.
368.

If the flame of a miner’s safety lamp in a manhole extinguishes within 5 minutes, the sewer certainly contains

A. ydrogen sulphide
B. arbon dioxide
C. ethane
D. xygen
Answer» C. ethane
369.

For trunk sewers more than 1.25 m in diameter, the ratio of the maximum daily sewage flow to the average daily sewage flow is assumed

A. 0.5
B. 0
C. 0.5
D. 0
Answer» B. 0
370.

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. 00 mm dia
B. 50 mm dia
C. 25 mm dia
D. ll of these
Answer» D. ll of these
371.

The rational formula for peak drainage discharge, was evolved by

A. ruhling
B. loyd David
C. uichling
D. ll of these
Answer» E.
372.

In normal conditions, the period for sludge digestion, is

A. 0 days
B. 0 days
C. 0 days
D. 0 days
Answer» D. 0 days
373.

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

A. .15 D
B. .25 D
C. .5 D
D. .75 D
Answer» D. .75 D
374.

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

A. ² (0.011d + 0.785H)/Q
B. (0.022d + 0.085H)/Q
C. (0.785d + 0.011H)/Q
D. (0.285d + 0.011H)/Q
Answer» B. (0.022d + 0.085H)/Q
375.

During purification process of sewage the gas given off, is

A. arbon dioxide
B. ydrogen
C. mmonia
D. ll the above
Answer» E.
376.

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 20°C, the D.O. concentration was 5 mg/l. The BOD of raw sewerage is

A. 00 mg/l
B. 00 mg/l
C. 00 mg/l
D. 00 mg/l
Answer» D. 00 mg/l
377.

The minimum diameter of a sewer is kept

A. 0 cm
B. 5 cm
C. 0 cm
D. 5 cm
Answer» C. 0 cm
378.

The most efficient cross-section of sewers in a combined sewerage system is

A. arabolic
B. ircular
C. ectangular
D. ew egged
Answer» C. ectangular
379.

Facultative bacteria survive in

A. he presence of oxygen
B. he absence of oxygen
C. oth cases A and B
D. either A nor B
Answer» D. either A nor B
380.

Dry weather flow is:

A. verage daily rate of flow
B. verage monthly rate of flow
C. verage annual rate of flow
D. ater supply allowance per capita
Answer» E.
381.

Are available in size Stoneware sewers

A. 0 cm
B. 5 cm
C. 0 cm
D. ll the above
Answer» E.
382.

The minimum diameter of sewer to be adopted is

A. 0 cm
B. 2.5 cm
C. 5 cm
D. 5 cm
Answer» D. 5 cm
383.

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. 0 mg/l
B. 00 mg/l
C. 50 mg/l
D. 50 mg/l
Answer» E.
384.

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. 00 ppm
B. 25 ppm
C. 50 ppm
D. one of these
Answer» D. one of these
385.

If a 2% solution of sewage sample is incubated for 5 days at 20°C and the dissolved oxygen depletion was found to be 8 mg/l. The BOD of the sewage is

A. 00 mg/l
B. 00 mg/l
C. 00 mg/l
D. 00 mg/l
Answer» E.
386.

Acid regression stage of sludge digestion at a temperature 21°C extends over a period of

A. 5 days
B. 0 days
C. 0 days
D. 0 days
Answer» E.
387.

If the depletion of oxygen is found to be 5 ppm after incubating a 2.5% solution of sewage sample for 5 days at 21°C, B.O.D. of the sewage is

A. 0 ppm
B. 00 ppm
C. 50 ppm
D. 00 ppm
Answer» E.
388.

The discharge per unit plan area of a sedimentation tank, is generally called

A. ver flow rate
B. urface loading
C. ver flow velocity
D. ll the above
Answer» E.
389.

Which one of the following statements regarding septic tanks is wrong?

A. gap of 7.5 cm between the bottom of the covering slab and the top level of scum is provided
B. he outlet invert level is kept 5 to 7.5 cm below the inlet invert level
C. he minimum width of septic level is 90 cm
D. he depth of tank is kept equal to its width
Answer» E.
390.

The sewage treatment in septic tanks is due to

A. naerobic decomposition
B. erobic decomposition
C. arasitic decomposition
D. one of these
Answer» B. erobic decomposition
391.

Nitrogen cycle of sewage, is

A. iberation of ammonia-formation of nitrites-formation of nitrates-liberation of nitrogen
B. iberation of nitrogen-liberation of ammonia-formation of nitrites- formation of nitrates
C. iberation of nitrogen-formation of nitrates-formation of nitrites-liberation of ammonia
D. ormation of nitrates-formation of nitrites-liberation of nitrates-liberation of nitrates
Answer» B. iberation of nitrogen-liberation of ammonia-formation of nitrites- formation of nitrates
392.

hydraulically equivalent, the relationship which holds good, is

A. 8/3 = 4 b8/3
B. 3/8 = 4 b3/8
C. 2/3 = 4 b2/3
D. 3/2 = 4 b3/2
Answer» B. 3/8 = 4 b3/8
393.

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

A. ’ = 0.64 D
B. ’ = 0.74 D
C. ’ = 0.84 D
D. ’ = 0.94 D
Answer» D. ’ = 0.94 D
394.

The quantity of liquid waste which flows in sewers during the period of rainfall, is known

A. anitary sewage
B. ndustrial waste
C. torm sewage
D. one of these
Answer» D. one of these
395.

The value of Chezy’s constant C = 157.6/(1.81 + K/ ) is used in

A. hezy’s formula
B. azin’s formula
C. utter’s formula
D. anning’s formula
Answer» C. utter’s formula
396.

Drop manholes are the manholes

A. ithout entry ladders
B. ithout manhole covers
C. ith depths more than 3.5 m
D. aving drains at different levels
Answer» E.
397.

The bottom of the sewage inlet chamber of septic tanks, is provided an outward slope

A. in 5
B. in 10
C. in 15
D. in 20
Answer» C. in 15
398.

The drop man holes are generally provided in sewers for

A. 3 hours.
B. industrial areas
C. large town ships
D. hilly town ships
Answer» D. hilly town ships
399.

The sewage discharge in a detritus tank of a treatment plant is 576 litres/sec with flow velocity of 0.2 m/sec. If the ratio of width to depth is 2, the depth is

A. none of these.
B. 100 cm
C. 110 cm
D. 120 cm
Answer» D. 120 cm
400.

The ratio of maximum sewage flow to average sewage flow for trunk mains having diameters more than 1.25 m, is

A. neither (a) nor (b).
B. 1.5
C. 2
D. 3
Answer» B. 1.5