MCQOPTIONS
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MCQOPTIONS
This section includes 260 Mcqs, each offering curated multiple-choice questions to sharpen your Civil Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
_A drop manhole is provided if$? |
| A. | A sewer drops from a height |
| B. | A branch sewer joins the main sewer at higher level |
| C. | A lamp is inserted to check obstruction |
| D. | None of these |
| Answer» C. A lamp is inserted to check obstruction | |
| 152. |
_The gas which may cause explosion in sewers, is$? |
| A. | Carbondioxide |
| B. | Methane |
| C. | Ammonia |
| D. | Carbon monoxide |
| Answer» C. Ammonia | |
| 153. |
_A well oxidized sewage contains nitrogen mainly as$? |
| A. | Nitrates |
| B. | Nitrites |
| C. | Free ammonia |
| D. | None of these |
| Answer» B. Nitrites | |
| 154. |
_In septic tanks,$? |
| A. | Free board of 0.3 m may be provided |
| B. | The baffles or tees are extended up to top level of scum |
| C. | The clear space between the baffle top and covering slab is about 7.5 cm |
| D. | All the above |
| Answer» E. | |
| 155. |
_The ratio of design discharge to the surface area of a sedimentation tank is called$? |
| A. | Surface loading |
| B. | Overflow rate |
| C. | Overflow velocity |
| D. | All of these |
| Answer» E. | |
| 156. |
_The design period in years for pumping plants, is$? |
| A. | 1 |
| B. | 2 to 3 |
| C. | 3 to 5 |
| D. | 5 to 10 |
| Answer» E. | |
| 157. |
_Facultative bacteria survive in$? |
| A. | The presence of oxygen |
| B. | The absence of oxygen |
| C. | Both cases A and B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 158. |
_Hydraulic mean radius is$? |
| A. | Mean radius of sewer |
| B. | Difference in heads between two points in circular pipes |
| C. | Mean of radii in a pipe line of varying cross -sections |
| D. | Cross-sectional area/wetted perimeter |
| Answer» E. | |
| 159. |
_The bottom of the sewage inlet chamber of septic tanks, is provided an outward slope$? |
| A. | 1 in 5 |
| B. | 1 in 10 |
| C. | 1 in 15 |
| D. | 1 in 20 |
| Answer» C. 1 in 15 | |
| 160. |
_Water content of sewage is about$? |
| A. | 90 % |
| B. | 95 % |
| C. | 99 % |
| D. | 9.9 % |
| Answer» E. | |
| 161. |
_During purification process of sewage the gas given off, is$? |
| A. | Carbon dioxide |
| B. | Hydrogen |
| C. | Ammonia |
| D. | All the above |
| Answer» E. | |
| 162. |
_The most efficient cross section of sewers in a separate sewerage system is$? |
| A. | Parabolic |
| B. | Circular |
| C. | Rectangular |
| D. | New egged |
| Answer» C. Rectangular | |
| 163. |
_Rate of flow of sewage is generally assumed$? |
| A. | More than the rate of water supply |
| B. | Equal to the rate of water supply |
| C. | Less than the rate of water supply |
| D. | At 150 litres per capita |
| Answer» E. | |
| 164. |
_For a grit chamber, if the recommended velocity of flow is 0.2 m/sec and detention period is 2 minutes, the length of the tank, is$? |
| A. | 16 m |
| B. | 20 m |
| C. | 24 m |
| D. | 30 m |
| Answer» D. 30 m | |
| 165. |
_The pressure exerted by$? |
| A. | The sewage when running full from inside, is called internal pressure |
| B. | The internal pressure if any, causes tensile stress in the pipe material |
| C. | Pressure sewers are designed to be safe in tension |
| D. | All the above |
| Answer» E. | |
| 166. |
_Before discharging the foul sewage into rivers, it is generally treated by$? |
| A. | Screening |
| B. | Sedimentation |
| C. | Oxidation |
| D. | All the above |
| Answer» E. | |
| 167. |
_With self cleansing velocity in sewers$? |
| A. | Silting occurs at bottom |
| B. | Scouring occurs at bottom |
| C. | Both silting and scouring occur at bottom |
| D. | Neither silting nor scouring occurs at bottom |
| Answer» E. | |
| 168. |
_In primary sedimentation, the 0.2 mm inorganic solids get separated if specific gravity is$? |
| A. | 2.25 |
| B. | 2.50 |
| C. | 2.55 |
| D. | 2.65 |
| Answer» E. | |
| 169. |
_Large diameter sewers subjected to external pressure alone, are reinforced$? |
| A. | Near the inner surface of the pipe |
| B. | Near the outer surface of the pipe |
| C. | Both A and B |
| D. | With elliptical cage |
| Answer» E. | |
| 170. |
_The use of coarse screens for the disposal of sewage, may be dispensed with by$? |
| A. | Comminutor |
| B. | Shredder |
| C. | Both A and B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 171. |
_The flow velocity in detritus tanks is$? |
| A. | 0.05 m/sec |
| B. | 0.09 m/sec |
| C. | 1.25 m/sec |
| D. | None of these |
| Answer» C. 1.25 m/sec | |
| 172. |
In 1000 kg of sewage, the total solids approximate$? |
| 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 | |
| 173. |
For the COD test of sewage, organic matter is oxidised by K‚ÇÇCr‚ÇÇO‚Çá in the presence of$? |
| A. | H‚ÇÇSO‚ÇÑ |
| B. | HNO‚ÇÉ |
| C. | HCl |
| D. | None of these |
| Answer» B. HNO‚Äö√á√â | |
| 174. |
The minimum diameter of sewer to be adopted is$? |
| A. | 10 cm |
| B. | 12.5 cm |
| C. | 15 cm |
| D. | 25 cm |
| Answer» D. 25 cm | |
| 175. |
Are available in size Stoneware sewers$? |
| A. | 10 cm |
| B. | 15 cm |
| C. | 20 cm |
| D. | All the above |
| Answer» E. | |
| 176. |
The sludge does not contain waste water from$? |
| A. | Bath rooms |
| B. | Wash basins |
| C. | Kitchen sinks |
| D. | Toilets |
| Answer» E. | |
| 177. |
The settling velocity of the particles larger than 0.06 mm in a settling tank of depth 2.4 is 0.33 m per sec. The detention period recommended for the tank, is$? |
| A. | 30 minutes |
| B. | 1 hour |
| C. | 1 hour and 30 minutes |
| D. | 2 hours |
| Answer» E. | |
| 178. |
If the grit in grit chambers is 4.5 million litres per day, its cleaning is done$? |
| A. | Manually |
| B. | Mechanically |
| C. | Hydraulically |
| D. | Electrically |
| Answer» B. Mechanically | |
| 179. |
Acid regression stage of sludge digestion at a temperature 21°C extends over a period of$? |
| A. | 15 days |
| B. | 30 days |
| C. | 60 days |
| D. | 90 days |
| Answer» E. | |
| 180. |
If a 2% solution of sewage sample is incubated for 5 days at 20°C and the dissolved oxygen depletion was found to be 8 mg/l. The BOD of the sewage is$? |
| A. | 100 mg/l |
| B. | 200 mg/l |
| C. | 300 mg/l |
| D. | 400 mg/l |
| Answer» E. | |
| 181. |
In very first stage of decomposition of the organic matter in sewage$? |
| A. | Nitrites are formed |
| B. | Nitrates are formed |
| C. | Carbondioxide is formed |
| D. | Ammonia is formed |
| Answer» E. | |
| 182. |
hydraulically equivalent, the relationship which holds good, is$? |
| A. | D8/3 = 4 b8/3 |
| B. | D3/8 = 4 b3/8 |
| C. | D2/3 = 4 b2/3 |
| D. | D3/2 = 4 b3/2 |
| Answer» B. D3/8 = 4 b3/8 | |
| 183. |
The sewage treatment in septic tanks is due to$? |
| A. | Anaerobic decomposition |
| B. | Aerobic decomposition |
| C. | Parasitic decomposition |
| D. | None of these |
| Answer» B. Aerobic decomposition | |
| 184. |
The standard B.O.D. of water is taken for$? |
| A. | 1 day |
| B. | 2 days |
| C. | 3 days |
| D. | 5 days |
| Answer» E. | |
| 185. |
Maximum permissible velocity 1.5 m/sec, is adopted in drains$? |
| A. | With beds of rocks and gravels |
| B. | Lined with stones |
| C. | Both A. and B. |
| D. | Neither A. nor B. |
| Answer» D. Neither A. nor B. | |
| 186. |
In trickling filter, B.O.D. is reduced to$? |
| A. | 30 to 40% |
| B. | 40 to 60% |
| C. | 60 to 80% |
| D. | 80 to 90% |
| Answer» D. 80 to 90% | |
| 187. |
1000 kg of sewage contains$? |
| A. | 0.112 kg in suspension |
| B. | 0.112 kg in solution |
| C. | 0.225 kg in solution |
| D. | Both A and C of above |
| Answer» E. | |
| 188. |
The width of a rectangular sewer is twice its depth while discharging 1.5 m/sec. The width of the sewer is$? |
| A. | 0.68 m |
| B. | 0.88 m |
| C. | 1.36 m |
| D. | 1.76 m |
| Answer» D. 1.76 m | |
| 189. |
For the survival of fish in a river stream, the minimum dissolved oxygen is prescribed$? |
| A. | 3 ppm |
| B. | 4 ppm |
| C. | 5 ppm |
| D. | 10 ppm |
| Answer» C. 5 ppm | |
| 190. |
For drainage pipes in buildings the test applied before putting them to use, is$? |
| A. | Water test |
| B. | Smoke test |
| C. | Straightness test |
| D. | All the above |
| Answer» C. Straightness test | |
| 191. |
5 days-biochemical oxygen demand (BOD5) is taken at a temperature of$? |
| A. | 0°C |
| B. | 15°C |
| C. | 20°C |
| D. | 25°C |
| Answer» D. 25¬¨‚àûC | |
| 192. |
Fresh sewage may become stale in$? |
| A. | One hour |
| B. | Two to three hours |
| C. | Three to four hours |
| D. | Six hours |
| Answer» D. Six hours | |
| 193. |
The algae dies out in the zone of$? |
| A. | Degradation |
| B. | Active decomposition |
| C. | Recovery |
| D. | Cleaner water |
| Answer» B. Active decomposition | |
| 194. |
The sewage is pumped up$? |
| A. | From low lying areas |
| B. | From flat areas |
| C. | From basements |
| D. | All the above |
| Answer» E. | |
| 195. |
The laying of sewers is done with$? |
| A. | Magnetic compass |
| B. | Theodolite |
| C. | Level |
| D. | Clinometer |
| Answer» D. Clinometer | |
| 196. |
The sewage is pumped up? |
| A. | From low lying areas |
| B. | From flat areas |
| C. | From basements |
| D. | All the above |
| Answer» E. | |
| 197. |
The algae dies out in the zone of? |
| A. | Degradation |
| B. | Active decomposition |
| C. | Recovery |
| D. | Cleaner water |
| Answer» B. Active decomposition | |
| 198. |
Fresh sewage may become stale in? |
| A. | One hour |
| B. | Two to three hours |
| C. | Three to four hours |
| D. | Six hours |
| Answer» D. Six hours | |
| 199. |
The laying of sewers is done with? |
| A. | Magnetic compass |
| B. | Theodolite |
| C. | Level |
| D. | Clinometer |
| Answer» D. Clinometer | |
| 200. |
Primary treatment of sewage consists of removal of? |
| A. | Large suspended organic solids |
| B. | Oil and grease |
| C. | Sand and girt |
| D. | Floating materials |
| Answer» B. Oil and grease | |