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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.
151. |
Pick up the incorrect statement from the following ? |
A. | Septic tanks are horizontal continuous flow type of sedimentation tanks |
B. | Septic tanks are generally provided a detention period of 12 to 36 hours |
C. | Septic tanks are completely covered and high vent shafts are provided for the escape of foul gases |
D. | None of these |
Answer» E. | |
152. |
Pick up the incorrect statement from the following for allowing workers to enter sewers_______________? |
A. | The particular manhole and one manhole on upstream and one manhole on downstream should remain open for 30 minutes |
B. | Proper tests for the presence of poisonous gases must be carried out |
C. | The men entering the manhole should be advised to smoke in the sewer |
D. | Warning signals should be erected |
Answer» D. Warning signals should be erected | |
153. |
Pick up the in-correct statement from the following? |
A. | Manholes are provided in sewer pipes at suitable intervals |
B. | Catch basins are generally provided in sewers for carrying drainage discharge |
C. | Inlets are generally provided in all sewers |
D. | None of these |
Answer» D. None of these | |
154. |
Pick up the incorrect size of stone ware sewers_________________? |
A. | 52.5 cm |
B. | 67.5 cm |
C. | 82.5 cm |
D. | None of these |
Answer» E. | |
155. |
Pick up the correct statement from the following _________________? |
A. | The materials separated by screens, is called screenings |
B. | The screenings are disposed off either by burning or by burial or by dumping |
C. | The process of burning the screenings, is known as compositing |
D. | All the above |
Answer» E. | |
156. |
pH value of sludge during alkaline regression stage, is__________________? |
A. | More than 7 |
B. | Less than 7 |
C. | Less than 6 |
D. | More than 6 |
Answer» B. Less than 7 | |
157. |
Pathogens (or pathogenic bacterias) in water may cause___________________? |
A. | Typhoid |
B. | Cholera |
C. | Dysentery |
D. | All the above |
Answer» E. | |
158. |
Oxidation process results in the formation of___________________? |
A. | Carbon dioxide |
B. | Nitrates |
C. | Sulphates |
D. | All the above |
Answer» E. | |
159. |
No treatment of the sewage is given if dilution factor is_____________? |
A. | Less than 150 |
B. | Between 150 to 200 |
C. | Between 200 to 300 |
D. | More than 500 |
Answer» E. | |
160. |
Nitrogen cycle of sewage, is____________________? |
A. | Liberation of ammonia-formation of nitrites-formation of nitrates-liberation of nitrogen |
B. | Liberation of nitrogen-liberation of ammonia-formation of nitrites- formation of nitrates |
C. | Liberation of nitrogen-formation of nitrates-formation of nitrites-liberation of ammonia |
D. | Formation of nitrates-formation of nitrites-liberation of nitrates-liberation of nitrates |
Answer» B. Liberation of nitrogen-liberation of ammonia-formation of nitrites- formation of nitrates | |
161. |
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. | |
162. |
Lead caulked joints are used for laying____________________? |
A. | Stone ware pipes |
B. | Earthenware pipes |
C. | C.I. pipes |
D. | G.I. pipes |
Answer» C. C.I. pipes | |
163. |
Lead acetate test in sewer manhole is done to test the presence of ____________________? |
A. | Methane gas |
B. | Hydrogen sulphide |
C. | Carbondioxide gas |
D. | Diesel vapours |
Answer» C. Carbondioxide gas | |
164. |
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. | |
165. |
Kjeldahl nitrogen is a mixture of___________________? |
A. | Ammonia and nitrogen |
B. | Nitrogen and organic nitrogen |
C. | Organic nitrogen and ammonia |
D. | All the above |
Answer» E. | |
166. |
It is customary to design a sewer for D.W.F. on the basis of________________? |
A. | Average demand |
B. | Twice the average demand |
C. | Thrice the average demand |
D. | Four times the average demand |
Answer» D. Four times the average demand | |
167. |
Inter-distance between ventilation columns in a sewer line is kept__________________? |
A. | 25 to 50 m |
B. | 50 m to 100 m |
C. | 100 m to 150 m |
D. | 150 m to 300 m |
Answer» E. | |
168. |
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. | |
169. |
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% | |
170. |
In the activated sludge process__________________? |
A. | Aeration is continued till stability |
B. | Aeration is done with an admixture of previously aerated sludge |
C. | Sludge is activated by constant stirring |
D. | Water is removed by centrifugal action |
Answer» C. Sludge is activated by constant stirring | |
171. |
In SI units the power of sound is represented in __________________? |
A. | Kgs |
B. | Joules |
C. | Newtons |
D. | Watts |
Answer» E. | |
172. |
In sewers the highest non-scouring velocity is achieved in________________? |
A. | Glazed bricks sewers |
B. | Cast iron sewers |
C. | Cement concrete sewers |
D. | Stone ware sewers |
Answer» B. Cast iron sewers | |
173. |
In sewers the gas generally found, is_________________? |
A. | Hydrogen sulphide (H2S) |
B. | Carbon dioxide (CO2) |
C. | Methane (CH4) |
D. | All the above |
Answer» E. | |
174. |
In sewers the velocity of flow should not be_________________? |
A. | More than the self-cleansing velocity |
B. | Less than the self-cleansing velocity |
C. | Less than 10 m/sec |
D. | More than 20 m/sec |
Answer» C. Less than 10 m/sec | |
175. |
In sewers the effect of scouring is more on__________________? |
A. | Top side |
B. | Bottom side |
C. | Horizontal side |
D. | All sides |
Answer» C. Horizontal side | |
176. |
In sewers designed with self cleansing velocity________________? |
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 |
Answer» E. | |
177. |
In sewage, the solids in mg per litre is__________________? |
A. | 100 to 500 |
B. | 500 to 1000 |
C. | 1000 to 1500 |
D. | 1500 to 2000 |
Answer» C. 1000 to 1500 | |
178. |
In sewage having fully oxidised organic matter, the nitrogen exists in the form of________________? |
A. | Nitrites |
B. | Nitrates |
C. | Free ammonia |
D. | Aluminoid nitrogen |
Answer» C. Free ammonia | |
179. |
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. | |
180. |
In septic tanks, decomposition of organic bacteria, is done by_____________________? |
A. | Anaerobic bacteria |
B. | Aerobic bacteria |
C. | Both types of bacterias |
D. | None of these |
Answer» B. Aerobic bacteria | |
181. |
In R.C. sewer pipes, the percentage longitudinal reinforcement to the cross-sectional area of concrete is kept________________? |
A. | 10.0 |
B. | 5.0 |
C. | 2.0 |
D. | 0.25 |
Answer» E. | |
182. |
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. | |
183. |
In olden days the type of section adopted in trunk and out fall sewers was__________________? |
A. | Parabolic shaped |
B. | Horse shoe shaped |
C. | Egg shaped |
D. | Circular shaped |
Answer» C. Egg shaped | |
184. |
In normal conditions, the period for sludge digestion, is_______________? |
A. | 10 days |
B. | 20 days |
C. | 30 days |
D. | 60 days |
Answer» D. 60 days | |
185. |
In detritus tanks______________________? |
A. | Flow velocity is kept 0.09 m/sec |
B. | Detention period is kept 3 to 4 minutes |
C. | Organic and inorganic materials are separated |
D. | All the above |
Answer» E. | |
186. |
In circular sewers if depth of flow is 0.2 times the full depth, the nominal gradient,______________? |
A. | Is only provided |
B. | Is doubled |
C. | Is trebled |
D. | Is not enough |
Answer» C. Is trebled | |
187. |
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. | D |
B. | D /2 |
C. | D/3 |
D. | D/4 |
Answer» E. | |
188. |
In case of sewer lines_________________? |
A. | Water test is carried out to check water tightness of the joints |
B. | Test for straightness is carried out with the help of a lamp and mirror |
C. | Obstruction test is carried out with the help of smooth ball of diameter 13 mm |
D. | All the above |
Answer» E. | |
189. |
In case of Imhoff tanks_____________________? |
A. | The shape is rectangular |
B. | Detention period is 2 hours |
C. | The velocity of flow is restricted to 0.30 m/minute |
D. | All the above |
Answer» E. | |
190. |
In areas where light rains are uniformly distributed throughout the year, the type of sewerage system to be adopted is_______________? |
A. | Separate system |
B. | Combined system |
C. | Partially combined system |
D. | None of these |
Answer» C. Partially combined system | |
191. |
In areas where rainy season is limited to a few months, the type of sewerage system recommended is__________________? |
A. | Combined system |
B. | Partially separate system |
C. | Separate system |
D. | None of these |
Answer» D. None of these | |
192. |
In a trickling filter_________________? |
A. | Filtration process is used |
B. | Biological action is used |
C. | Neither A. nor B. |
D. | Both A. and B. |
Answer» C. Neither A. nor B. | |
193. |
In a sludge tank, the gas mainly produced, is_________________? |
A. | Oxygen |
B. | Nitrogen |
C. | Hydrogen |
D. | Carbon dioxide |
Answer» E. | |
194. |
In a sludge digestion tank if the moisture content of sludge V1 litres is reduced from p1 % to p2 % the volume V2 is____________________? |
A. | [(100 + P1)/(100 – P2)] V1 |
B. | [(100 – P1)/(100 + P2)] V1 |
C. | [(100 – P1)/(100 – P2)] V1 |
D. | [(100 + P2)/(100 – P1)] V1 |
Answer» D. [(100 + P2)/(100 – P1)] V1 | |
195. |
In a sedimentation tank (length L, width B, depth D) the settling velocity of a particle for a discharge Q, is____________________? |
A. | Q/(B × D) |
B. | Q/(L × D) |
C. | Q/L |
D. | Q/(B × L) |
Answer» E. | |
196. |
In a grit chamber of a sewage treatment plant ____________________? |
A. | Flow velocity 0.15 m to 0.3 m/sec is kept |
B. | Depth of 0.9 m to 1.20 m is kept |
C. | One minute of detention period is kept |
D. | All the above |
Answer» E. | |
197. |
In a fully mechanised composting plant, involves________________? |
A. | Mechanized receipt |
B. | Mechanized segregation |
C. | Mechanized pulverising of refuse |
D. | All of these |
Answer» E. | |
198. |
In a city the ratio of the drainage to sewage is 20, the percentage discharge passing through non-monsoon periods, is_____________________? |
A. | 5 |
B. | 10 |
C. | 15 |
D. | 20 |
Answer» E. | |
199. |
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 | |
200. |
Imhoff cone is used to measure________________? |
A. | Total organic solids |
B. | Total solids |
C. | Total in organic solids |
D. | Settleable solids |
Answer» E. | |