NEET Previous Year Questions (2016-2024): Environmental Issues (Old NCERT) | IBPS PO Prelims & Mains Preparation - Bank Exams PDF Download

Q.1.  The thickness of ozone in a column of air in the atmosphere is measured in terms of :     (NEET 2023)
(a) Dobson units
(b) Decibels
(c) Decameter
(d) Kilobase
Ans. a

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). Noise is measured in decibels.

Q.2. Which one of the following statements is NOT correct?    (NEET 2023)
(a) The micro-organisms involved in biodegradation of organic matter in a sewage polluted water body consume a lot of oxygen causing the death of aquatic organisms
(b) Algal blooms caused by excess of organic matter in water improve water quality and promote fisheries
(c) Water hyacinth grows abundantly in eutrophic water bodies and leads to an imbalance in the ecosystem dynamics of the water body
(d) The amount of some toxic substances of industrial waste water increases in the organisms at successive trophic levels
Ans. b

Algal bloom imparts a distinct colour to the water bodies. It causes deterioration of the water quantity and fish mortality. 

Q.3. Which of the following statement is correct?    (NEET 2023)
(a) Eutrophication refers to increase in domestic sewage and waste water in lakes.
(b) Biomagnification refers to increase in concentration of the toxicant at successive trophic levels.
(c) Presence of large amount of nutrients in water restricts Algal Bloom
(d) Algal Bloom decreases fish mortality
Ans. b

Increase in the concentration of the toxicant at successive trophic level is called biomagnification. Large amount of nutrients in water promotes growth of algal bloom. Algal bloom increases fish mortality. Eutrophication refers to the natural aging of a lake by nutrient enrichment of its water.

Q.4.  Given below are two statements:     (NEET 2023)
Statement I: Electrostatic precipitator is most widely used in thermal power plant.
Statement II : Electrostatic precipitator in thermal power plant removes ionising radiations.
In the light of the above statements, choose the most appropriate answer from the options given below:
(a) Both Statement I and Statement II are correct.
(b) Both Statement I and Statement II are incorrect.
(c) Statement I is correct but Statement II is incorrect.
(d) Statement I is incorrect but Statement II is correct.
Ans. c

Electrostatic precipitator is most widely used in thermal power plants.
It can remove over 99 percent particulate matter present in the exhaust from a thermal power plant.

Q.5. The device which can remove particulate matter present in the exhaust from a thermal power plant is:      (NEET 2022)
(a) Incinerator
(b) Electrostatic Precipitator
(c) Catalytic Convertor
(d) STP

Ans. (b)
Solution. There are several ways of removing particulate matter; the most widely used of which is the electrostatic precipitator, which can remove over 99% of particulate matter present in the exhaust from a thermal power plant. It has electrode wires that are maintained at several thousand volts, which produce a corona that releases electrons. These electrons attach to dust particles giving them a net negative charge. The collecting plates are grounded and attract the charged dust particles.

Q.6. The entire fleet of buses in Delhi were converted to CNG from diesel. In reference to this, which one of the following statements is false?       (NEET 2022)
(a) The same diesel engine is used in CNG buses making the cost of conversion low
(b) It is cheaper than diesel
(c) It can not be adulterated like diesel
(d) CNG burns more efficiently than diesel

Ans. (a)
Solution. The true statements are:
(i) CNG is cheaper than diesel.
(ii) It can not be adulterated like diesel or petrol.
(iii) CNG burns more efficiently than diesel.

Q.7. Given below are two statements:       (NEET 2022)
Statement I: In a scrubber, the exhaust from the thermal plant is passed through the electric wires to charge the dust particles.
Statement II: Particulate matter (PM 2.5) cannot be removed by a scrubber but can be removed by an electrostatic precipitator.
In the light of the above statements, choose the most appropriate answer from the options given below:
(a) Both Statement I and Statement II are incorrect
(b) Statement I is correct but Statement II is incorrect
(c) Statement I is incorrect but Statement II is correct
(d) Both Statement I and Statement II are correct

Ans. (c)
Solution. In this scrubber, the exhaust is passed through a spray of water or lime. Electrostatic precipitators can capture fine particles like those that are smaller than 2.5 microns in diameter, which are especially dangerous if released because they can be drawn deep into the lungs and can trigger inflammatory reactions. Scrubber cannot separate these.

Q.8. Dobson units are used to measure thickness of:     (NEET 2021)
(a) Ozone
(b) Troposphere
(c) CFCs
(d) Stratosphere
Ans. (a)
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.9. Montreal protocol was signed in 1987 for control of :     (NEET 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
Ans. (d)
Solution.
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.10. Snow - blindness in Antarctic region is due to :      (NEET 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
Ans. (d)
Solution.
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.11. Which of the following methods is the most suitable for disposal of nuclear waste?    (NEET 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
Ans. (a)

Q.12. Which of the following pairs of gases is mainly responsible for greenhouse effect?    (NEET 2019)
(a) Carbon dioxide and methane
(b) Ozone and ammonia
(c) Oxygen and nitrogen
(d) Nitrogen and sulphur dioxide
Ans. (a)
Solution.
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.13. Polyblend, a fine powder of recycled modified plastic, has proved to be a good material for    (NEET 2019)
(a) Making tubes and pipes
(b) Making plastic sacks
(c) Use as a fertiliser
(d) Construction of roads
Ans. (d)
Solution.
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.14. Which of the following protocols did aim reducing emission of chlorofluorocarbons into atmosphere?    (NEET 2019)
(a) Geneva Protocol
(b) Montreal Protocol
(c) Kyoto Protocol
(d) Gothenburg Protocol
Ans. (b)
Solution.
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.15. Which of the following statements about ozone is correct?    (NEET 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.
Ans. (d)

Q.16. In stratosphere, which of the following elements acts as a catalyst in degradation of ozone and release of molecular oxygen?    (NEET 2018)
(a) Carbon
(b) Cl
(c) Fe
(d) Oxygen
Ans. (b)
Solution.
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.17. Which of the following is a secondary pollutant?    (NEET 2018)
(a) CO
(b) CO₂ 
(c) SO₂ 
(d) O₃
Ans. (d)
Solution.
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.18. World Ozone Day is celebrated on    (NEET 2018)
(a) 5^th June
(b) 21^st April
(c) 16^th September
(d) 22^nd April
Ans. (c)

Q.19. Match the items given in column I with those in column II and select the correct option given below.    (NEET 2018)

Ans. (c)

Q.20. Which one of the following statements is not valid for aerosols?    (NEET 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.
Ans. (b)
Solution.
Aerosols are harmful environmental pollutants which have negative effects on agriculture.

Q.21. Biochemical Oxygen Demand (BOD) may not be a good index for pollution for water bodies receiving effluents from    (NEET 2016)
(a) Domestic sewage
(b) Dairy industry
(c) Petroleum industry
(d) Sugar industry
Ans. (c)
Solution.
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.22. A lake which is rich in organic waste may result in    (NEET 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
Ans. (d)
Solution.
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.23. The highest DDT concentration in aquatic food chain shall occur in    (NEET 2016)
(a) Phytoplankton
(b) Sseagull
(c) Crab
(d) EEL
Ans. (b)
Solution.
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.24. Depletion of which gas in the atmosphere can lead to an increased incidence of skin cancers?    (NEET 2016)
(a) Ammonia
(b) Methane
(c) Nitrous oxide
(d) Ozone
Ans. (d)
Solution.
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.25. Joint Forest Management Concept was introduced in India during    (NEET 2016)
(a) 1980s
(b) 1990s
(c) 1960s
(d) 1970s
Ans. (a)
Solution.
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.26. A river with an inflow of domestic sewage rich in organic waste may result in    (NEET 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
Ans. (b)