civil engineering Mcqs
1251. The population of a town in three consecutive years are 5000, 7000 and 8400 respectively. The population of the town in the fourth consecutive year according to geometrical increase method is________________?
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A. 10920

B. 9800

C. 10100

D. 9500

1252. Most suitable section of sewer in separate sewage system is________________?
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A. circular section

B. standard form of egg shaped sewer

C. modified egg shaped section

D. rectangular section

1253. It is observed that in a certain sinusoidal oscillation, the amplitude is linearly dependent on the frequency f. If the maximum velocity during the oscillation is V, then V must be proportional to_________________?
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A. f

B. 1/f

C. 1/f2

D. f2
1254. The most common cause of acidity in water is_______________?
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A. hydrogen

B. oxygen

C. nitrogen

D. carbon dioxide
1255. The member forces in a statically in determinate truss____________________?
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A. may be obtained by graphic statics

B. can be obtained by graphic statics by trial and error

C. cannot be obtained by graphic statics

D. can be obtained by graphic statics

1256. Which of the following has highest coefficient of discharge ?
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A. venturimeter

B. sharp edged orifice

C. Bordas mouthpiece running full

D. CipoUetti weir

1257. The velocity distribution for laminar flow through a circular tube__________________?
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A. is constant over the cross-section

B. none of the above

C. varies parabolically with maximum at the centre

D. varies linearly from zero at walls to maximum at centre

1258. In chlorination, with the rise in temperature of water, death rate of bacteria____________?
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A. remains unaffected

B. decreases

C. none of the above

D. increases
1259. For laminar flow in a pipe of circular cross-section, the Darcys friction factor f is________________?
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A. inversely proportional to Reynolds number and directly proportional to pipe wall roughness

B. directly proportional to Reynolds number and independent of pipe wall roughness

C. inversely proportional to Reynolds number and indpendent of pipe wall roughness

D. directly proportional to pipe wall roughness and independent of Reynolds number

1260. The pathogens can be killed by_______________?
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A. chlorination

B. none of the above

C. oxidation

D. nitrification

1261. Which of the following velocity potentials satisfies continuity equation ?
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A. cosx

B. x2y

C. x2 + y2

D. x2-y2
1262. Alum as a coagulant is found to be most effective when pH range of water is______________?
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A. 4 to 6

B. 2 to 4

C. 6 to 8

D. 8 to 10

1263. Corrosion in concrete sewers is caused by______________?
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A. dissolved oxygen

B. nitrogen

C. chlorine

D. septic conditions
1264. If the kinetic energy and potential energy of a simple harmonic oscillator of amplitude A are both equal to half the total energy, then the displacement is equal to_________________?
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A. A

B. AV2

C. A/V2

D. A/2

1265. The minimum dissolved oxygen which should always be present in water in order to save the aquatic life is______________?
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A. 4 ppm

B. 1 ppm

C. 10 ppm

D. 40 ppm

1266. The hourly variation factor is usually taken as______________?
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A. 1.8

B. 2.7

C. 2

D. 1.5
1267. The potential energy of a particle falling through a straight shaft drilled through the earth (assumed homogenous and spherical) is proportional to____________________?
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A. r

B. 1/r

C. log r

D. r2
1268. The discharge over a broad crested weir is maximum when the depth of flow is_______________?
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A. H/2

B. 2 H/5

C. 2 H/3

D. H/3

1269. Which of the following methods of analysis of water distribution system is most suitable for long and narrow pipe system ?
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A. electrical analysis method

B. equivalent pipe method

C. circle method

D. Hardy cross method

1270. In a forced vortex motion, the velocity of flow is________________?
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A. inversely proportional to its radial distance from the axis of rotation

B. inversely proportional to the square of its radial distance from the axis of rotation

C. directly proportional to its radial distance from axis of rotation

D. directly proportional to the square of its radial distance from the axis of rotation

1271. The velocity of flow of water in a sedimentation tank is about__________________?
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A. 15 to 30 cm/hour

B. 5 to 10 cm/sec.

C. 15 to 30 cm/minute

D. 15 to 30 cm/sec.

1272. Newtons law of viscosity relates________________?
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A. shear stress and rate of angular deformation

B. shear stress, viscosity and temperature

C. viscosity and rate of angular deformation

D. intensity of pressure and rate of angular deformation

1273. With the same cross-sectional area and immersed in same turbulent flow, the largest total drag will be on__________________?
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A. a circular disc of plate held normal to flow

B. a streamlined body

C. a cylinder

D. a sphere

1274. The working conditions in imhoff tanks are_______________?
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A. aerobic in lower compartment and anaerobic in upper compartment

B. aerobic only

C. anaerobic only

D. anaerobic in lower compartment and aerobic in upper compartment
1275. Which of the following is not a water borne disease ?
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A. dysentery

B. typhoid

C. maleria

D. cholera

1276. As compared to cast iron pipes, steel pipes are______________?
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A. heavier

B. costlier

C. stronger

D. less susceptible to corrosion

1277. The discharge of a liquid of kinematic viscosity 4 cm2/sec through a 8 cm dia-meter pipe is 3200n cm7sec. The type of flow expected is__________________?
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A. laminar flow

B. not predictable from the given data

C. turbulent flow

D. transition flow

1278. Settling velocity increases with_______________?
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A. specific gravity of solid particles

B. temperature of liquid

C. depth of tank

D. size of particles

1279. If velocity is zero over l/3rd of a cross-section and is uniform over remaining 2/3rd of the cross-section, then the correction factor for kinetic energy is__________________?
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A. 9/4

B. 2-Mar

C. 3-Apr

D. 27/8

1280. The major loss of energy in long pipes is due to_______________?
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A. gradual contraction or enlargement

B. sudden contraction

C. friction

D. sudden enlargement

1281. One Newton is equivalent to________________?
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A. 981 dyne

B. 1 kg-wt

C. 9.81 kg-wt

D. 1/9.81 kg-wt
1282. For the same solid content, if the quantity of sludge with moisture content of 98% is X, then the quantity of sludge with moisture content of 96% will be__________________?
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A. X/4

B. X/2

C. 2X

D. X

1283. As compared to rapid sand filters, slow sand filters give______________?
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A. slower filtration rate

B. lesser efficiency in removal of bacteria

C. higher filtration rate

D. higher efficiency in removal of bacteria </strong>

E. correct answer is?

1284. Disinfection of water results in______________?
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A. removal of turbidity

B. killing of disease bacteria

C. complete sterilisation

D. removal of hardness

1285. The position of center of pressure on a plane surface immersed vertically in a static mass of fluid is______________?
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A. none of the above

B. at the centroid of the submerged area

C. always above the centroid of the area

D. always below the centroid of the area
1286. The type of sewer which is suitable for both combined and separate system is_____________?
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A. horse-shoe type sewer

B. circular sewer

C. egg shaped sewer

D. semi-elliptical sewer

1287. The hydraulic mean depth (HMD. for an egg-shaped sewer flowing two-third full is_______________?
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A. none of the above

B. equal to HMD when flowing full

C. less than HMD when flowing full

D. greater than HMD when flowing full
1288. The method of analysis of distribution system in which the domestic supply is neglected and fire demand is considered is________________?
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A. Hardy cross method

B. equivalent pipe method

C. electrical analysis method

D. circle method
1289. The major disadvantage of lime soda process of water softening is that_________________?
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A. it is unsuitable for softening the water of excessive hardness

B. huge amount of precipitate is formed which creates a disposal problem

C. it is unsuitable for turbid and acidic water

D. the effluent cannot be reduced to zero hardness

1290. The alum, when added as a coagulant in water_______________?
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A. does not affect pH value of water

B. increases pH value of water

C. does not require alkalinity in water for flocculation

D. decreases pH value of water
1291. The force polygon representing a set of forces in equilibrium is a_____________________?
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A. parallelogram

B. open polygon

C. closed polygon

D. triangle

1292. The process in which the chlorination is done beyond the break point is known as_________________?
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A. break point chlorination

B. prechlorination

C. super chlorination

D. post chlorination

1293. In a BOD test, 1.0 ml of raw sewage was diluted to 100 ml and the dissolved oxygen concentration of diluted sample at the beginning was 6 ppm and it was 4 ppm at the end of 5 day incubation at 20C. The BOD of raw sewage will be___________?
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A. 300 ppm

B. 200 ppm

C. 400 ppm

D. 100 ppm

1294. Rate of change of angular momentum is equal to_______________?
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A. force

B. impulse

C. linear momentum

D. torque
1295. The rate of Alteration of pressure filters is_________________?
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A. equal to that of slow sand filters

B. greater than that of rapid sand filters

C. less than that of slow sand filters

D. in between the filtration rate of slow sand filters and rapid sand filters

1296. The settling velocity of a particle in a sedimentation tank increases if_________________?
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A. the surface area of tank is increased

B. the depth of tank is decreased

C. none of the above

D. particle size is decreased

1297. Which of the following is an incorrect statement ?
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A. Coefficient of contraction of a venturimeter is unity

B. Flow nozzle is cheaper than venturimeter but has higher energy loss

C. Discharge is independent of orientation of venturimeter whether it is horizontal, vertical or inclined

D. None of the above statement is correct.
1298. The ratio of average velocity to maximum velocity for steady laminar flow in circular pipes is_______________?
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A. 3-Feb

B. 2-Mar

C. 2

D. 1/2
1299. The specific gravity of sewage is_______________?
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A. slightly less than 1

B. much greater than 1

C. equal to 1

D. slightly greater than 1
1300. A sewer that receives the discharge of a number of house sewers is called________________?
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A. intercepting sewer

B. house sewer

C. submain sewer

D. lateral sewer