civil engineering Mcqs
2901. Sewer pipes are designed for maximum discharge with 25% to 33% vacant cross-sectional area for__________________?
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A. Under estimates of maximum and average flows

B. Unexpected large scale infiltration of stream water

C. All of the above

D. Unexpected increase in the population

2902. If the diameter of sewer is 225 mm, the gradient required for generating self cleansing velocity, is___________________?
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A. 1 in 100

B. 1 in 60

C. 1 in 120

D. None of these

2903. The sewer which transports the sewage to the point of treatment, is called________________?
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A. House sewer

B. Out-fall sewer

C. Branch sewer

D. Main sewer

2904. For evaporation and measurement of settable solids, the apparatus used, is________________?
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A. An Imhoff cone

B. A test tube

C. A jar

D. A breaker

2905. pH value of sludge during alkaline regression stage, is__________________?
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A. More than 7

B. Less than 7

C. More than 6

D. Less than 6

2906. The minimum recommended diameter of sewers, is_________________?
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A. 5 cm

B. 20 cm

C. 10 cm

D. 15 cm
2907. The width of a rectangular sewer is twice its depth while discharging 1.5 m/sec. The width of the sewer is______________?
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A. 0.68 m

B. 1.36 m

C. 1.76 m

D. 0.88 m

2908. In sewers the effect of scouring is more on__________________?
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A. All sides

B. Top side

C. Horizontal side

D. Bottom side
2909. If 850 kg liquid occupies volume of one cubic meter, men 0.85 represents its_______________?
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A. specific weight

B. specific density

C. specific mass

D. none of the above

E. specific gravity
2910. Fluid is a substance which offers no resistance to change of_________________?
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A. temperature

B. flow

C. pressure

D. volume

E. shape
2911. The flow velocity in detritus tanks is________________?
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A. None of these

B. 0.05 m/sec

C. 1.25 m/sec

D. 0.09 m/sec
2912. The buoyancy depends on__________________?
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A. pressure of the liquid displaced

B. none of the above.

C. depth of immersion

D. mass of liquid displaced

E. viscosity of the liquid

2913. Cowl is provided at___________________?
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A. Upper end of ventilating column

B. Lower end of ventilating column

C. Upper end of the manhole

D. First step in manhole

2914. The normal value of over flow rates for plain primary sedimentation tanks, ranges between________________?
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A. 50,000 to 60,000 litres/sqm/day

B. 80,000 to 100,000 litres/sqm/day

C. 40,000 to 50,000 litres/sqm/day

D. 25,000 to 35,000 litres/sqm/day

2915. Which of the following is the unit of kinematic viscosity _________________?
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A. poise

B. stoke

C. none of the above

D. faraday

E. pascal

2916. A safety lamp when inserted in the upper portion of a manhole causes flames. It indicates the presence of______________?
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A. Petrol vapours

B. Carbondioxide gas

C. Methane gas

D. Hydrogen sulphide gas

2917. For very great pressures, viscosity of moss gases and liquids __________________?
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A. increases

B. remains same

C. decreases

D. shows erratic behaviour

E. none of the above.

2918. The laying of sewers is done with____________________?
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A. Clinometer

B. Theodolite

C. Level

D. Magnetic compass

2919. Clogging of sewers, is caused due to_______________?
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A. Low discharge

B. Greasy and oily matters

C. All the above

D. Silting

2920. A circular sewer section is preferred to because__________________?
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A. It provides maximum hydraulic mean depth

B. It provides maximum area for a given perimeter

C. It is cheaper in construction

D. All the above
2921. As compared to fresh river water, sea water contains oxygen_________________?
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A. 10% more

B. 20% less

C. 20% more

D. 10% less

2922. In a sedimentation tank (length L, width B, depth D) the settling velocity of a particle for a discharge Q, is____________________?
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A. Q/(L D)

B. Q/(B L)

C. Q/L

D. Q/(B D)

2923. In areas where rainy season is limited to a few months, the type of sewerage system recommended is__________________?
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A. Partially separate system

B. None of these

C. Separate system

D. Combined system

2924. 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_______________?
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A. D = 0.64 D

B. D = 0.84 D

C. D = 0.94 D

D. D = 0.74 D

2925. In a static fluid__________________?
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A. viscosity is nil

B. only normal stresses can exist

C. fluid pressure is zero

D. linear deformation is small

E. resistance to shear stress is small

2926. The most efficient cross-section of sewers in a combined sewerage system is________________?
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A. Rectangular

B. New egged

C. Circular

D. Parabolic

2927. The reduced levels of the string at the consecutive sight rails A and B are 203.575 m, 203.475 m respectively. If the difference of their R.D.s is 10 m, the gradient of the sewer line is_________________?
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A. 1 in 503 upward

B. 1 in 100 downward

C. 1 in 100 upward

D. 1 in 500 upward

2928. The value of the coefficient of compressibility for water at ordinary pressure and temperature in kg/cm is equal to _________________?
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A. 10,000

B. 1000

C. 2700

D. 21,000.

E. 2100

2929. The density of water is 1000 kg/m3 at __________________?
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A. 0C

B. all temperature

C. 4C D. 20C

D. 0K

2930. In a city the ratio of the drainage to sewage is 20, the percentage discharge passing through non-monsoon periods, is_____________________?
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A. 5

B. 20

C. 10

D. 15

2931. Pick up the incorrect statement from the following?
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A. The mixture of water and waste products, is called sewage

B. The treated sewage effluents, are generally used for irrigating the crops

C. The process of collecting, treating and disposing off the sewage, is called sewerage

D. The old convergence system was definitely better than water carried sewerage system
2932. If w is the specific weight of liquid and k the depth of any point from the surface, then pressure intensity at that point will be____________________?
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A. w/h

B. h/w

C. h

D. h/wh

E. wh
2933. The tendency of a liquid surface to contract is due to the following property_________________?
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A. elasticity

B. cohesion

C. adhesion

D. surface tension

E. viscosity

2934. In sewers designed with self cleansing velocity________________?
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A. The bottom is silted

B. The bottom is scoured

C. Both silting and scouring occur at the bottom

D. Neither silting nor scouring occurs at the bottom
2935. If cohesion between molecules of a fluid is greater than adhesion between fluid and glass, then the free level of fluid in a dipped glass tube will be_________________?
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A. lower than the surface of liquid

B. the same as the surface of liquid

C. higher than the surface of liquid

D. unpredictable

E. none of the above

2936. Rate of flow of sewage is generally assumed__________________?
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A. Equal to the rate of water supply

B. Less than the rate of water supply

C. More than the rate of water supply

D. At 150 litres per capita
2937. The value of mass density in kgsecVm4 for water at 0C is_______________?
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A. 1

B. 1000

C. 91

D. 100

E. 101.9
2938. Dried sewage after treatment is used as____________________?
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A. Chemical for lowering B.O.D.

B. Building material

C. Fertilizer

D. Base material for paints

2939. A liquid would wet the solid, if adhesion forces as compared to cohesion forces are_________________?
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A. less at low temperature and more at high temperature

B. there is no such criterion

C. less

D. more

E. equal

2940. For detecting the nitrites in the sewage, the matching colour may be developed by adding_________________?
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A. Sulphuric acid and napthamine

B. None of these

C. Potassium permanganate

D. Phenol-di -sulphuric acid potassium hydroxide

2941. For detecting the nitrates in sewage, the colour may be developed by adding________________?
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A. Phenol-di -sulphuric acid and potassium hydroxide

B. None of these

C. Sulphuric acid and napthamine

D. Potassium permanganate

2942. Uniform flow occurs when___________________?
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A. the magnitude and direction of the velocity do not change from point to point in the fluid

B. the velocity of successive fluid pai-ticles, at any point, is the same at successive periods of time

C. the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plsr.e

D. the direction and magnitude of the velocity at all points are identical

E. velocity, depth, pressure, etc. change from point to point in the fluid flow

2943. A large Roynold number is indication of_________________?
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A. steady flow

B. highly turbulent flow

C. turbulent flow

D. laminar flow

E. smooth and streamline flow

2944. The fluid forces considered in the Navier Stokes equation are__________________?
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A. gravity, viscous and turbulent

B. none of the above

C. pressure, viscous and turbulent

D. gravity, pressure and viscous

E. gravity, pressure and turbulent

2945. Non uniform flow occurs when ____________________?
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A. the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plane

B. the velocity of successive fluid par-ticles, at any point, is the same at suc-cessive periods of time

C. the direction and magnitude of the velocity at all points are identical

D. velocity, depth, pressure, etc. change from point to point in the fluid flow

E. the magnitude aricf direction of the velocity do not change from point to point in the fluid

2946. In an immersed body, center of pressure is ____________________?
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A. at the center of gravity

B. unpredictable

C. below be center of gravity

D. could be above or below e.g. depending on density of body and liquid

E. above the center of gravity

2947. Pitot tube is used for measurement of__________________?
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A. pressure

B. flow

C. velocity

D. dsscharge

E. viscosity

2948. The minimum width of the fire escape stairs shall be?
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A. 2.0 m

B. 1.25 m

C. 1.00 m

D. 1.5 m

2949. The difference of pressure between the inside and outside of a liquid drop is_____________?
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A. none of the above

B. = T/r

C. = Txr

D. p = 2T/r

E. p = T/2r

2950. The vapour pressure over the concave surface is________________?
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A. less man the vapour pressure over the plane surface

B. zero

C. equal to the vapour pressure over the plane surface

D. greater than the vapour pressure over the plane surface

E. none of the above