Engineering Questions with Answers - Multiple Choice Questions

Environmental Science MCQ – Ozone Depletion

1 - Question

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

Answer: d
Explanation: The concentration of ozone is about 10 ppm in the ozone layer and only 0.3 ppm in the entire atmosphere.




2 - Question

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

Answer: a
Explanation: In 1913, Henri Buisson and Charles Fabry discovered the ozone layer and later its properties were studied by G.M.B. Dobson.




3 - Question

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

Answer: c
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 - Question

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

Answer: b
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 - Question

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

Answer: a
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 - Question

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

Answer: b
Explanation: The ozone layer is found in high concentrations of 2-8ppm at an altitude of 20-40km.




7 - Question

Nitrogen also helps in preventing UV rays from reaching the Earth.
a) True
b) False

View Answer

Answer: a
Explanation: Nitrogen prevents extremely short wavelengths or vacuum UV radiations (10-100nm) from reaching the surface.




8 - Question

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

Answer: b
Explanation: UV-B radiations of 315-280nm is responsible for causing sunburns, genetic damage as well as skin cancer.




9 - Question

The long UV-B radiations are important for vitamin D production of the skin.
a) True
b) False

View Answer

Answer: a
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 - Question

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

Answer: c
Explanation: The ozone levels in the northern hemisphere are at maximum during the spring season.




11 - Question

When was the ozone hole discovered?
a) 1974
b) 1964
c) 1994
d) 1984

View Answer

Answer: d
Explanation: The ozone hole was discovered in the year 1984 by Jonathan Franklin, Joseph Farman and Brian Gardiner.




12 - Question

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

Answer: d
Explanation: The phenomenon of the ozone hole occurred in the Antarctic region primarily due to catalytic breakdown of ozone molecules by halogenated compounds.




13 - Question

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

Answer: d
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 - Question

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

Answer: a
Explanation: EESC stands for equivalent effective stratospheric chlorine is used to measure the chlorine equivalent of halogens that can deplete the ozone layer.




15 - Question

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

Answer: b
Explanation: The Montreal protocol bans the production of halons, trichloroethane, CFCs and carbon tetrachloride.

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