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Q.1. Dobson units are used to measure thickness of: (2021)
Solution. The thickness of the ozone in a column of air from the ground to the top of the atmosphere is measured in terms of Dobson units (DU).
Q.2. Montreal protocol was signed in 1987 for control of : (2020)
(a) Release of Green House gases
(b) Disposal of e-wastes
(c) Transport of Genetically modified organisms from one country to another
(d) Emission of ozone depleting substances
Montreal Protocol, is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion.
Q.3. Snow - blindness in Antarctic region is due to : (2020)
(a) High reflection of light from snow
(b) Damage of retina caused by infra -red rays
(c) Freezing of fluids in the eye by low temperature
(d) Inflammation of cornea due to high dose of UV - B radiation
In human eye, cornea absorbs UV-B radiation, and a high dose of UV-B causes inflammation of cornea, called snow-blindness It is a painful eye condition caused by overexposure to ultraviolet (UV) light. Cornea sunburn results due to the effects of UV light on the cornea.
Q.4. Which of the following methods is the most suitable for disposal of nuclear waste? (2019)
(a) Bury the waste within rocks deep below earth’s surface
(b) Shoot the waste into space
(c) Bury the waste under Antarctic ice-cover
(d) Dump the waste within rocks under ocean
Q.5. Which of the following pairs of gases is mainly responsible for greenhouse effect? (2019)
(a) Carbon dioxide and methane
(b) Ozone and ammonia
(c) Oxygen and nitrogen
(d) Nitrogen and sulphur dioxide
The various greenhouse gases are CO2, CH4, CFCs and N2O. Excessive use o f fossil fuels is adding more CO2 to atmosphere. This increase in concentration of greenhouse gases has led to considerable heating of earth leading to global warming. During the past century, the temperature of earth has increased by 0.6°C.
Q.6. Polyblend, a fine powder of recycled modified plastic, has proved to be a good material for (2019)
(a) Making tubes and pipes
(b) Making plastic sacks
(c) Use as a fertiliser
(d) Construction of roads
Polyblend, a fine powder of recycled modified plastic is mixed with bitumen that is used to lay roads. Polyblend and bitumen when used to lay roads, enhanced bitumen’s water repellent properties and helped to increase road life by factor of three.
Q.7. Which of the following protocols did aim reducing emission of chlorofluorocarbons into atmosphere? (2019)
(a) Geneva Protocol
(b) Montreal Protocol
(c) Kyoto Protocol
(d) Gothenburg Protocol
Montreal Protocol, is an international treaty, signed at Montreal in 1987 to control the emission of ozone-depleting substances [chlorofluorocarbons (CFCs), nitrogen oxides, SO2, halon, mcthylchloroform, etc.].
Q.8. Which of the following statements about ozone is correct? (2019)
(a) Tropospheric ozone protects us from UV radiations.
(b) Stratospheric ozone is 'bad'
(c) Tropospheric ozone is 'good'
(d) Stratospheric ozone protects us from UV radiations.
Q.9. In stratosphere, which of the following elements acts as a catalyst in degradation of ozone and release of molecular oxygen? (2018)
UV rays act on chlorofluorocarbons (CFCs) releasing active chlorine (Cl, CIO) which further reacts with ozone in sequential manner thereby converting it into oxygen.
Q.10. Which of the following is a secondary pollutant? (2018)
Secondary pollutants are produced photochemically from primary pollutants and are called photochemical oxidants. These include peroxyacyl nitrates (PAN), ozone, aldehydes, smog, etc. CO, CO2 and SO2 are prim ary pollutants.
Q.11. World Ozone Day is celebrated on (2018)
(a) 5th June
(b) 21st April
(c) 16th September
(d) 22nd April
Q.12. Match the items given in column I with those in column II and select the correct option given below. (2018)
|Column I||Column II|
|A. Eutrophication||(i) UV-B radiation|
|B. Sanitary landfill||(ii) Deforestation|
|C. Snow blindness||(iii) Nutrient enrichment|
|D. Jhum cultivation||(iv) Waste disposal|
Q.13. Which one of the following statements is not valid for aerosols? (2017)
(a) They alter rainfall and monsoon patterns.
(b) They cause increased agricultural productivity.
(c) They have negative impact on agricultural land.
(d) They are harmful to human health.
Aerosols are harmful environmental pollutants which have negative effects on agriculture.
Q.14. Biochemical Oxygen Demand (BOD) may not be a good index for pollution for water bodies receiving effluents from (2016)
(a) Domestic sewage
(b) Dairy industry
(c) Petroleum industry
(d) Sugar industry
Biochemical oxygen demand (BOD) is the measure of oxygen required by aerobic decomposers for biochemical degradation of the biodegradable organic materials. BOD indicates the degree of organic pollution in water. Petroleum is not degraded by decomposer microbes.
Q.15. A lake which is rich in organic waste may result in (2016)
(a) Increased population of aquatic organisms due to minerals
(b) Drying of the lake due to algal bloom
(c) Increased population of fish due to lots of nutrients
(d) Mortality of fish due to lack of oxygen
High amount of organic waste in a lake will trigger and activate decomposer microbes which will decompose organic waste. Biochemical Oxygen Demand (BOD) of this lake will shoot up and decomposers will utilise most of the dissolved oxygen present in lake. Consequently, the level of dissolved oxygen will go down to alarming extent. Aquatic animals like fish which totally depend on the oxygen dissolved in water will ultimately die.
Q.16. The highest DDT concentration in aquatic food chain shall occur in (2016)
DDT is non-biodegradable and is not metabolised within the body of an organism rather it accumulates in the fat tissues therefore its concentration goes on increasing from one trophic level to another of a food chain, highest amount being present in top consumer, i.e., it shows biomagnification. In an aquatic food chain seagull is the top carnivore therefore will possess highest concentration of DDT.
Q.17. Depletion of which gas in the atmosphere can lead to an increased incidence of skin cancers? (2016)
(c) Nitrous oxide
Ozone layer or shield is present in stratosphere. It functions as a shield against strong UV radiations coming from sun. UV radiations are very harmful and may cause mutations in living organisms. Thinning of ozone layer increases the amount of UV radiations reaching the earth. It would increase occurrence of cataract, skin cancers, dimming of eye sight, photobombing, deficient functioning of immune system, etc.
Q.18. Joint Forest Management Concept was introduced in India during (2016)
In India, Joint Forest Management was started in 1980s. Village and tribal communities are being involved in development and protection of degraded forests on share basis.
Q.19. A river with an inflow of domestic sewage rich in organic waste may result in (2016)
(a) An increased production of fish due to biodegradable nutrients
(b) Death of fish due to lack of oxygen
(c) Drying of the river very soon due to algal bloom
(d) Increased population of aquatic food web organisms