Insufficient washing of sand grains in a rapid sand filter causes__________________?

Related Mcqs:

1. Water filtration rate in a rapid sand filter ranges from ______________ kilolitres/m2/hr?

   A. 0.1 to 1
   B. 3 to 6
   C. 10 to 15
   D. 15 to 20

2. Water filtration rate in a slow sand filter ranges from ____________ litres/m2/hr?

   A. 10 to 20
   B. 100 to 200
   C. 1500 to 2500
   D. 4000 to 5000

3. Thermal pollution due to excessive heat & temperature in the working place causes__________________?

   A. Reduction in working efficiency of manpower
   B. Fatigue
   C. High breathing rate
   D. All A., B. & C.

4. Presence of excess fluorine in water causes__________________?

   A. Dental cavity
   B. Tooth decay
   C. Fluorosis
   D. Respiratory disease

5. Bag filter design is predominantly dependent on gas temperature, as it affects the gas density & viscosity and the selection of filtering material. The pressure drop in a bag filter is__________________?

   A. Inversely proportional to viscosity of gas
   B. Proportional to the viscosity & density of the gas
   C. Proportional to the pressure of the gas
   D. Both B. and C.

6. Inhalation of lead compounds present in automobile exhaust (using leaded petrol) causes__________________?

   A. Blood poisoning
   B. Anaemia
   C. Nervous system disorder
   D. All A., B. & C.

7. Brown spots in fabrics will be caused by washing with water containing large amount of___________________?

   A. Iron
   B. Zinc
   C. Iodine
   D. Bromine

8. Coal washing waste water containing about 3% suspended solids (comprising of clay, slate, stone etc.) is treated for solid particles removal ?

   A. By chemical coagulation
   B. In sedimentation tanks equipped with mechanical scrapper
   C. In vacuum filter
   D. In clarifiers

9. The type of bacteria which is active in trickling filter during biological treatment of sewage is the _____________ bacteria?

   A. Anaerobic
   B. Saprophytic
   C. Aerobic
   D. Parasitic

10. A considerable part of the harmful ultraviolet radiation of the sum does not reach the earth surface, because of the fact that, there is a layer of _____________ high above earth’s atmosphere, which absorbs it?

    A. Hydrogen
    B. Carbon dioxide
    C. Ozone
    D. None of these