80% less than 200 mesh size particles are called____________________?

Related Mcqs:

1. 5-200 μm size particles are called__________________?

   A. Colloids or aerosols
   B. Powder
   C. Dust
   D. Smoke

2. Carbonaceous particles having size less than 1 μm are called___________________?

   A. Grit
   B. Aggregates
   C. Aerosols
   D. Smoke

3. Which is the best and the most effective method for the removal of organic contaminant present in the polluted water in very small quantity (say < 200 mg/litre) ?

   A. Lagooning
   B. Activated carbon adsorption
   C. Biological oxidation pond
   D. Chemical coagulation

4. Which is the most efficient dust removal equipment for removal of submicronic dust particles from blast furnace gas ?

   A. Packed scrubber
   B. Gravity settling chamber
   C. Electrostatic precipitator
   D. Hydrocyclone

5. 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

6. Particles having diameter greater than 75 μm (micrometer = 10-6 mm) are called__________________?

   A. Grit
   B. Dust
   C. Powder
   D. Smoke

7. . Operating principle of cyclone separator is based on the action of _______________ dust particles?

   A. Diffusion of
   B. Centrifugal force on
   C. Gravitational force on
   D. Electrostatic force on

8. Sooty and sulphurous smog formed due to combustion of fossil fuels particularly in winter, continues throughout the day and night. When the moist atmospheric air’s water vapor condenses on the solid particles of smoke thereby forming smog (smoke + fog), it causes_________________?

   A. Poor visibility due to sky darkening
   B. Irritation in eyes
   C. Respiratory trouble
   D. All A., B. and C.

9. Which of the following dust collection equipments is the least efficient (for sub-micronic particles) ?

   A. Dust catcher (gravity type)
   B. Cyclone separator
   C. Bag filter
   D. Hollow wet scrubber

10. For existence of aquatic life in water, the dissolved oxygen content in it, should not be less than ______________ ppm?

    A. 10000
    B. 5
    C. 500
    D. 1000