Railway Science (Environment -Ozone)

Total Questions: 16

11. Australia has one of the highest skin cancer incidence and mortality rates in the world. It is caused mainly due to the exposure to UV rays. Which of the following UV rays are responsible for this? [RRB NTPC CBT - I (09/03/2021) Morning]

Correct Answer: (c) Both UV-A & UV-B
Solution:

UV-A rays penetrate deeper into the skin, while UV-B rays are more likely to cause sunburn. Both types of UV rays can damage DNA, which can lead to skin cancer. Australia has one of the highest rates of skin cancer in the world. This is due to a number of factors, including the country's location near the equator, the high levels of UV radiation, and the fair skin of many Australians.

12. What is the ozone layer composed of? [RRB NTPC CBT - I (11/03/2021) Evening]

Correct Answer: (a) Tri-oxygen
Solution:

Ozone is a gas that is made up of three oxygen atoms. Ozone in the stratosphere is a product of UV radiations acting on dioxygen (O₂) molecules. The UV radiations split apart molecular oxygen into free oxygen (O) atoms.These oxygen atoms combine with the molecular oxygen to form ozone.

13. The largest holes in the ozone layer have been observed in 2020 over which of the following continents? [NTPC CBT - I 23/07/2021 (Morning)]

Correct Answer: (b) Antarctica
Solution:

It was the longest-lasting and one of the largest and deepest holes since the ozone layer monitoring began 40 years ago. The ozone layer is a thin part of Earth's atmosphere that absorbs almost all of the sun's harmful ultraviolet light. Chlorofluorocarbons or CFCs are the main cause of ozone layer depletion.

14. Which of the following greenhouse gases is NOT included under the Kyoto Protocol? [RRB NTPC CBT - I ( 23/07/2021) Evening]

Correct Answer: (d) Ozone
Solution:

The Montreal Protocol on Substances that Deplete the Ozone Layer, was done in 1987. The Kyoto Protocol covers six categories of greenhouse gas (GHG) emissions – carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride (SF₆). The Kyoto Protocol was adopted on 11 December 1997. Due to a complicated ratification process, it came into force on 16 February 2005.

15. Which of the following classes of chemicals can damage the ozone layer? [RRB ALP Tier - II (23/01/2019) Afternoon]

Correct Answer: (b) Chlorofluorocarbon
Solution:

chlorofluorocarbons (CFCs) are nontoxic, nonflammable chemicals containing carbon, chlorine, and fluorine atoms. Used - manufacture aerosol sprays, blowing agents for foams and packing materials, solvents, and refrigerants.

16. _____ is/are radiation emitted by the sun and responsible for the cause of skin cancer. [RRB Group D 27/09/2018 (Evening)]

Correct Answer: (d) Ultraviolet radiation
Solution:

Ultraviolet radiation (UV) : Discovered by - Johann Wilhelm Ritter. Wavelength - (10 - 400 nm), Frequency - 800 THz to 30 PHz. It is the best source of natural vitamin D.
It damages the genetic material (DNA) in your skin cells. A portion of UV rays are absorbed by the ozone layer.
Gamma rays (Strongest type of radiation) - High frequency radioactive radiation consisting of high-energy photons.
Alpha rays - Positively charged particles, Weakest type of radiation, The minimum penetration power and highest ionization power.
Beta rays - Negative charge particles, Dangerous when contact with the body.