A. The concentric layer in atmosphere which contains about 70% of the total mass of atmosphere
and characterised by a steady decrease in temperature is called stratosphere
B. Stratosphere is rich in ozone and is located just above the troposphere
C. Troposphere is a turbulent dusty zone containing much of water vapor and clouds
D. The earth’s atmosphere is an envelope of gases extending upto a height of about 200 kms
Related Mcqs:
- Pick out the wrong statement pertaining to ‘green house’ for the plants ?
A. ‘Green house’ (made of glass) allows visible sunlight (i.e., short wavelength solar radiation
like ultra-violet rays) to pass through the glass and heat up the soil thereby warming up plants
inside it
B. The emitted longer wavelength radiation (e.g., infrared) is partly reflected and partly absorbed
by the glass of the green house
C. ‘Green house effect’ in earth’s atmosphere is due to increasing CO2 level in atmosphere, where
CO2 acts like the glass of ‘green house’ thereby warming up the earth’s surface
D. ‘Green house’ is colder than the outside atmosphere - Pick out the wrong statement. A. Caustic embrittlement of boiler’s metallic parts is caused by high concentration of caustic soda in boiler feed water___________________?
B. Cooling and freezing of water kills the bacteria present in it
C. With increasing boiler operating pressure of steam, the maximum allowable concentration of
silica in feed water goes on decreasing
D. Dissolved oxygen content in high pressure boiler feed water should be nil - 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. - Pick out the one which is not a chemical coagulant ?
A. Aluminium sulphate
B. Ferrous sulphate
C. Hydrated lime
D. Chloramine - CFC (chloro fluoro carbon) is very highly reactive in causing depletion of ozone layer in the atmosphere. Each atom of chlorine liberated from CFC is capable of decomposing ________________ molecules of ozone?
A. 102
B. 105
C. 109
D. 1015 - The function of skimming tank in sewage treatment is to remove _____________ substances?
A. Dissolved solid
B. Suspended solid
C. Oil & fatty
D. Gritty & inorganic - Iron & manganese present as pollutant in water cannot be removed by__________________?
A. Ion exchange process
B. Oxidation followed by settling & filtration
C. Lime soda process or manganese zeolite process
D. Chlorination - World environment day is observed every year on the 5th of___________________?
A. June
B. December
C. July
D. September - Arsenic pollutant is not generated in _______________ industries?
A. Tanneries
B. Glass & ceramic
C. Beverages
D. Any of these - The maximum permissible noise level to which a man working in a chemical plant can be exposed for eight hours per day is about ____________ decibels?
A. 60
B. 90
C. 105
D. 120
