A. Nothing but black smoke
B. A combination of smoke and fog
C. A liquid particle resulting from vapor condensation
D. A solid particle e.g. fly-ash
Related Mcqs:
- 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. - Photochemical smog is formed from automobile exhaust ________________?
A. By reaction of hydrocarbon & nitric oxide in presence of sunlight
B. Appears only on sunny days
C. Is harmful for crops and trees also besides causing eye irritation & asthma
D. All A., B. & C. - Presence of high concentration of ozone and smog in atmospheric air causes the __________________?
A. Embrittlement & decrease of folding resistance of paper
B. Cracking of rubber products
C. Fading of dye on textiles
D. Damage of electrical insulator on high tension power line - Disinfection of water is done to remove ______________________?
A. Color
B. Bad taste
C. Foul odour
D. Bacteria - The term Biological Oxygen Demand (BOD) is used in relation to ______________________?
A. Potable water
B. Cooling water
C. Distilled water
D. Industrial effluents - Pick out the correct statement ?
A. Chemical oxygen demand (COD) is a measure of chemically oxidisable organic matter present
in water
B. COD is determined by oxidising the organic matter present in water with potassium
dichromate in cone, sulphuric acid solution at boiling temperature for specified time
C. COD is related to BOD of a given waste in water but the relationship varies for different
wastes. Typically COD of potable water may be 1-2 mg/litre
D. All A., B. and C. - Biological oxidation ponds remove organic matters present in the polluted water by _______________?
A. Using the activities of bacteria and other micro organisms
B. Aerobic oxidation
C. Both A. & B.
D. Neither A. nor B. - Removal of ______________ is accomplished by aeration of water?
A. Dissolved gases
B. Suspended solids
C. Dissolved solids
D. None of these - Noise level heard inside a bus in busy city traffic or inside a sub-way train corresponds to about ______________ decibels?
A. 75
B. 95
C. 120
D. 140 - Maximum permissible limit of mercury in human blood is ______________ micrograms/100 c.c?
A. 1
B. 7
C. 19
D. 82
