Aerobic activity is maximum_______________?

Related Mcqs:

1. The amount of oxygen consumed by the aerobic bacterias which cause the aerobic biological decomposition of sewage, is known_________________?

   A. Bio-Chemical Oxygen Demand (B.O.D.)
   B. Dissolved Oxygen (D.O.)
   C. Chemical Oxygen Demand (C.O.D.)
   D. None of these

2. To maintain aerobic biological activity, the moisture content of the compost mass should be about_________________?

   A. 45 %
   B. 50 %
   C. 55 %
   D. 60 %

3. Aerobic bacterias___________________?

   A. Flourish in the presence of free oxygen
   B. Consume organic matter as their food
   C. Oxidise organic matter in sewage
   D. All the above

4. Pick up the correct statement from the following ?

   A. The sewer pipes of sizes less than 0.4 m diameter are designed as running full at maximum discharge
   B. The sewer pipes of sizes greater than 0.4 m diameter are designed as running 2/3rd or 3/4th full at maximum discharge
   C. The minimum design velocity of sewer pipes is taken as 0.8 m/sec
   D. All the above

5. 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

6. The density of population over 40 hectares is 250/hectare. If water supply demand per day is 200 litres and sewage discharge is 80% of water supply, the sewage flow in sewers of separate system, is_____________________?

   A. 0.05552 cumec
   B. 0.05554 cumec
   C. 0.05556 cumec
   D. 0.0556 cumec

7. Ventilating shafts are provided to a sewer line at every__________________?

   A. 100 m
   B. 150 m
   C. 200 m
   D. 300 m

8. Dry water flow in a combined sewer, is______________________?

   A. Industrial sewage
   B. Domestic sewage
   C. Storm water
   D. Inclusive of domestic and industrial sewage but excludes storm water

9. The asbestos cement pipes are generally laid___________________?

   A. Horizontally
   B. Vertically
   C. At an angle of 30°
   D. At an angle of 60°

10. The sewers___________________?

    A. Must be of adequate size to avoid over flow
    B. Must flow under gravity ½ to ¾ full
    C. Must be laid at least 2 to 3 m deep to collect /water from the basements
    D. All the above