This set of Environmental Science Multiple Choice Questions & Answers (MCQs) focuses on “Ozone Depletion”.
1. What is the average concentration of ozone in the ozone layer of the atmosphere?
a) Nearly 100%
b) Greater than 90%
c) Between 10-50%
d) Less than 10ppm
View Answer
Explanation: The concentration of ozone is about 10 ppm in the ozone layer and only 0.3 ppm in the entire atmosphere.
2. Who discovered the ozone layer?
a) Henri Buisson & Charles Fabry
b) Carl Sagan & Charles Fabry
c) G.M.B Dobson
d) Carl Sagan &G.M.B Dobson
View Answer
Explanation: In 1913, Henri Buisson and Charles Fabry discovered the ozone layer and later its properties were studied by G.M.B. Dobson.
3. Which of the following devices can be used to measure ozone in the stratosphere from the ground?
a) Spectrometer
b) Photometer
c) Spectrophotometer
d) Spectro-ozonometer
View Answer
Explanation: The spectrophotometer developed by Dobson can be used to measure ozone in the stratosphere from the ground. The amount of ozone is measured in terms of – Dobson unit.
4. The ozone layer absorbs what range of wavelengths of the sun’s radiation?
a) 0.80 nm – 1.50 nm
b) 200 nm – 315 nm
c) 450 nm – 570 nm
d) 600 nm – 750 nm
View Answer
Explanation: The ozone layer absorbs the medium frequency UV radiations from the sun and hence protects the life forms at the surface from harm.
5. Who discovered the formation of ozone from photochemical reactions?
a) G.M.B Dobson
b) Sydney Chapman
c) Carl Sagan
d) Henri Buisson
View Answer
Explanation: Sydney Chapman was the physicist who discovered that stratospheric ozone if formed when the UV rays from the sun splits oxygen molecules, and the nascent oxygen combines with existing molecules to form ozone.
6. Between what altitudes, is the ozone layer found in highest concentrations?
a) 10-20km
b) 20-40km
c) 40-55km
d) 55-70km
View Answer
Explanation: The ozone layer is found in high concentrations of 2-8ppm at an altitude of 20-40km.
7. Nitrogen also helps in preventing UV rays from reaching the Earth.
a) True
b) False
View Answer
Explanation: Nitrogen prevents extremely short wavelengths or vacuum UV radiations (10-100nm) from reaching the surface.
8. Which of the following UV radiations is responsible for causing sun burns and skin cancer?
a) UV-A
b) UV-B
c) UV-C
d) All of the mentioned
View Answer
Explanation: UV-B radiations of 315-280nm is responsible for causing sunburns, genetic damage as well as skin cancer.
9. The long UV-B radiations are important for vitamin D production of the skin.
a) True
b) False
View Answer
Explanation: The longest of the UV-B radiations reach the surface of the earth is small fractions and aids in vitamin D production of the skin.
10. In which season is the ozone found at its maximum level in the northern hemisphere?
a) Winter
b) Summer
c) Spring
d) Autumn
View Answer
Explanation: The ozone levels in the northern hemisphere are at maximum during the spring season.
11. When was the ozone hole discovered?
a) 1974
b) 1964
c) 1994
d) 1984
View Answer
Explanation: The ozone hole was discovered in the year 1984 by Jonathan Franklin, Joseph Farman and Brian Gardiner.
12. The ozone hole is a phenomenon that has occurred in:
a) Arctic region
b) Northern temperate region
c) Southern temperate region
d) None of the mentioned
View Answer
Explanation: The phenomenon of the ozone hole occurred in the Antarctic region primarily due to catalytic breakdown of ozone molecules by halogenated compounds.
13. Which of the following chemicals are responsible for the depletion of the stratospheric ozone layer?
a) Refrigerants
b) Propellants
c) Foam-blowing agents
d) All of the mentioned
View Answer
Explanation: Refrigerants containing halocarbons, foam-blowing agents such as HFCs, halons, CFCs and freons as well as propellants containing halogenated compounds are responsible for depleting the ozone layer.
14. What does EESC stand for in context of ozone depleting compounds?
a) Equivalent Effective Stratospheric Chlorine
b) Equivalent Effective Stratospheric Chlorofluorocarbons
c) Equivalent Energy Saving Compounds
d) Energy Effective Stratospheric Compounds
View Answer
Explanation: EESC stands for equivalent effective stratospheric chlorine is used to measure the chlorine equivalent of halogens that can deplete the ozone layer.
15. The Montreal Protocol bans the production of which of the following chemical substances?
a) Chlorine, bromine, CFCs, freons
b) Carbon tetrachloride, halons, trichloroethane, CFCs
c) CFCs, bromine, halons, freons
d) CFCs, halons, freons
View Answer
Explanation: The Montreal protocol bans the production of halons, trichloroethane, CFCs and carbon tetrachloride.
Sanfoundry Global Education & Learning Series – Environmental Science.
To practice all areas of Environmental Science, here is complete set of 1000+ Multiple Choice Questions and Answers.
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