The most dangerous pollutant in vehicular emissions is____________________?

Related Mcqs:

1. Which one of the following gases is most significant as air pollutant ?

   A. Carbondioxide
   B. Oxygen
   C. Nitrogen
   D. Sulphur-dioxide

2. The sewer which resists sulphide corrosion, is____________________?

   A. Brick sewer
   B. Cast iron sewer
   C. R.C.C. sewer
   D. Lead sewer

3. 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. 100
   B. 1000
   C. 5000
   D. 10000

4. The maximum spacing of manholes specified by Indian standard in sewers upto 0.3 m diameter is____________________?

   A. 20 m
   B. 30 m
   C. 45 m
   D. 75 m

5. For non-scouring velocity 5 m/sec, the type of sewers generally preferred to, is____________________?

   A. Cast iron sewers
   B. Cement concrete sewers
   C. Glazed bricks sewers
   D. Stone ware sewers

6. If the depth of partial flow in a sewer of diameter 2 m, is 50 cm, its wetted perimeter is____________________ ?

   A. 1/3
   B. 0/2
   C. 0/3
   D. 2 /3

7. If is the diameter of upper circular portion, the area of cross-section of a standard egg shaped sewer, is____________________?

   A. D²
   B. D²
   C. D²
   D. D²

8. 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. 100 cm
   B. 110 cm
   C. 120 cm
   D. 150 cm

9. 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

10. 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