Railway Science (Environment -Ozone)

Total Questions: 16

1. What was the main objective of the agreement made by UNEP in 1987 ? [RRC Group D 23/08/2022 (Evening)]

Correct Answer: (d) Stabilizing the production of CFCs at the level of 1986
Solution:

Ozone is made up of three atoms of oxygen combined together by the action of ultraviolet (UV) radiation on oxygen gas. The ozone layer protects us from the harmful effects of UV radiation.

2. The manufacturing of refrigerators that do not release chlorofluorocarbons has been made mandatory throughout the world. How will this help to prevent ozone depletion? [RRC Group D 24/08/2022 (Evening)]

Correct Answer: (a) It will reduce the release of CFCs that react with ozone molecules.
Solution:

Chlorofluorocarbons (CFCs) - They break up only through sunlight, which divides their molecules, causing the release of chlorine (Cl).
Once the chlorine is released, it is able to react with ozone (O3), to form chlorine monoxide (ClO) and oxygen (O₂) i.e. Cl + O₃ = ClO + O₂ .
In 1987, the United Nations Environment Programme (UNEP) succeeded in forging an agreement to freeze CFC production at 1986 levels.
Ozone (O₃) is a molecule, and is mostly found in the stratosphere, where it protects us from the Sun’s harmful ultraviolet (UV) radiation.

3. What is the product of UV radiations acting on oxygen molecules at higher levels of the atmosphere? [RRC Group D 08/09/2022 (Morning)]

Correct Answer: (a) Ozone
Solution:

Ozone (O₃) is created primarily by ultraviolet radiation in the stratosphere. When high-energy ultraviolet rays strike ordinary oxygen molecules (O₂), they split the molecule into two single oxygen atoms, known as atomic oxygen. A freed oxygen atom combines with another oxygen molecule to form a molecule of ozone.

4. When did the ozone levels in the atmosphere start to reduce? [RRC Group D 09/09/2022 (Afternoon)]

Correct Answer: (c) 1980
Solution:

Ozone layer - a region in the earth’s stratosphere that contains high concentrations of ozone (O₃) and protects the earth from the harmful ultraviolet radiations of the sun.
Ozone layer depletion - gradual thinning of the earth’s ozone layer in the upper atmosphere caused due to the release of chemical compounds. September 16 - International Day for the Preservation of the Ozone Layer.

5. Where is the ozone hole located ? [RRC Group D 14/09/2022 (Evening)]

Correct Answer: (c) Over Antarctica
Solution:

Ozone (O₃) is a colorless, reactive oxidant gas that is a major constituent of atmospheric smog. It is present in the stratosphere. Vienna Convention (1985) - The first international agreement for the protection of the ozone layer.
Ozone layer depletion increases the amount of Ultraviolet rays that reach the Earth's surface. Ozone Depletion Substances - Chlorofluorocarbons (CFCs), Halons, Carbon tetrachloride, Methyl chloroform, Hydrofluorocarbons.

6. What will happen if the ozone layer becomes thinner? [RRC Group D 16/09/2022 (Afternoon)]

Correct Answer: (c) Cases of skin cancer will increase
Solution:

Ozone (O₃) layer - Region in the earth’s stratosphere that contains high concentrations of ozone and protects the earth from the harmful ultraviolet radiations of the sun.

7. In 1987, the United Nations Environment Programme (UNEP) succeeded in forging an agreement to freeze CFC production at _______levels. [RRC Group D 30/09/2022 (Evening)]

Correct Answer: (b) 1986
Solution:

Montreal Protocol: Finalized in 1987, is a global agreement to protect the stratospheric ozone layer by phasing out the production and consumption of ozone-depleting substances, mainly CFCs.
Some important protocols are the Vienna Convention (1985), Kyoto Protocol (1997), Rio Summit (1992), Ramsar Convention (1971) etc.

8. From the given options, select the one that CANNOT be listed among the long-run effects of ozone depletion. [RRB NTPC CBT - II (14/06/2022) Shift 1]

Correct Answer: (c) Increased amount of oxygen consumption in human beings
Solution:

Ozone is produced naturally in the stratosphere. Ozone layer depletion increases the amount of Ultraviolet (UV) rays that reach the Earth’s surface and causes some health issues among humans, such as skin diseases, cancer, sunburns, cataract, quick ageing and weak immune system. Strong ultraviolet rays may lead to minimal growth, flowering and photosynthesis in plants.

9. Which of the following is NOT an environmental concern? [RRB NTPC CBT - I (21/01/2021) Morning]

Correct Answer: (b) Raising ozone layer
Solution:

Ozone layer depletion - When chlorine and bromine atoms come into contact with ozone in the stratosphere then destroy ozone molecules which are damaging to human health by increasing skin cancers, eye cataracts and immune deficiency disorders due to ultraviolet rays.
Environmental concerns include pollution, overpopulation, waste disposal, climate change, global warming (long-term heating of Earth's surface), the greenhouse effect, etc.

10. Ozone layer is responsible for preventing harmful UV rays to enter the earth’s atmosphere. Which of the hydrocarbons is/are not responsible for depletion of the ozone layer? [RRB NTPC CBT - I (07/03/2021) Evening]

Correct Answer: (a) Asphalt
Solution:

Ozone (O₃) protects earth from UV radiation in the form of Ozone layer (naturally occurs in the stratosphere).