Ozone Layer

Total Questions: 47

11. The maximum concentration of ozone is found in which of following? [U.P.P.C.S. (Pre) 2018]

Correct Answer: (c) Stratosphere
Solution:The earth's atmosphere is divided into several layers and each layer plays an important role. The layer extending about 10-50 km is called the stratosphere. The ozone layer is mainly found in the lower portion of the stratosphere from approximately 15 to 30 kilometres above the Earth, though the thickness varies seasonally and geographically.

The ozone layer protects the Earth from the sun UV rays. 10% of the ozone layer is found in the troposphere and 90% in the stratosphere.

12. Ozone layer is above the earth's crust around- [R.A.S./R.T.S. (Pre) 2012]

Correct Answer: (d) 20 km.
Solution:The Ozone layer is mainly found in stratosphere from approximately 15 to 30 km above the Earth's surface. It's density varies seasonally and geographically. The Ozone Layer describes the protective layer of naturally occurring gas found about 10-50 km above the earth's surface. It protects us from harmful ultraviolet radiation. Ninety percent of the ozone in the atmosphere is in the Stratosphere, and 10 percent is in the Troposphere.

The ozone in the stratosphere is commonly known as the ozone layer. The total amount of Ozone in the Ozone Layer varies with location on the time scales that range from daily to seasonal. Stratospheric winds, chemical production, and ozone destruction cause the variations. Because of the seasonal wind patterns in the stratosphere, total ozone is generally lowest at the equator and highest near the poles.

Ozone Layer Depletion refers to the thinning the Ozone layer in the Earth's Stratosphere.
Ozone layer depletion is a thermodynamically unstable gas that readily decomposes into molecular oxygen. Normally, a dynamic equilibrium exists between the production and decomposition of ozone molecules. Ozone layer depletion occurs when this balance of stratospheric ozone is tipped in favour of destruction.

13. The ozone layer is found mainly in- [U.P.P.C.S. (Mains) 2012]

Correct Answer: (c) Stratosphere
Solution:The Ozone layer is mainly found in stratosphere from approximately 15 to 30 km above the Earth's surface. It's density varies seasonally and geographically. The Ozone Layer describes the protective layer of naturally occurring gas found about 10-50 km above the earth's surface. It protects us from harmful ultraviolet radiation. Ninety percent of the ozone in the atmosphere is in the Stratosphere, and 10 percent is in the Troposphere.

The ozone in the stratosphere is commonly known as the ozone layer. The total amount of Ozone in the Ozone Layer varies with location on the time scales that range from daily to seasonal. Stratospheric winds, chemical production, and ozone destruction cause the variations. Because of the seasonal wind patterns in the stratosphere, total ozone is generally lowest at the equator and highest near the poles.

Ozone Layer Depletion refers to the thinning the Ozone layer in the Earth's Stratosphere.
Ozone layer depletion is a thermodynamically unstable gas that readily decomposes into molecular oxygen. Normally, a dynamic equilibrium exists between the production and decomposition of ozone molecules. Ozone layer depletion occurs when this balance of stratospheric ozone is tipped in favour of destruction.

14. Which is the lowest layer of the Atmosphere? [U.P.P.C.S. (Mains) 2012]

Correct Answer: (d) Troposphere
Solution:The lowest region in the atmosphere is called troposphere. Its average height is 13 km. The thickness of the troposphere is maximum at the equator, deepest in the tropics up to 18 to 20 km and shallowest near the polar regions. After this come to the stratosphere, mesosphere, thermosphere and exosphere respectively.

The Ozone Layer describes the protective layer of naturally occurring gas found about 10-50 km above the earth's surface. It protects us from harmful ultraviolet radiation. Ninety percent of the ozone in the atmosphere is in the Stratosphere, and 10 percent is in the Troposphere.

The ozone in the stratosphere is commonly known as the ozone layer. The total amount of Ozone in the Ozone Layer varies with location on the time scales that range from daily to seasonal. Stratospheric winds, chemical production, and ozone destruction cause the variations. Because of the seasonal wind patterns in the stratosphere, total ozone is generally lowest at the equator and highest near the poles.

Ozone Layer Depletion refers to the thinning the Ozone layer in the Earth's Stratosphere.
Ozone layer depletion is a thermodynamically unstable gas that readily decomposes into molecular oxygen. Normally, a dynamic equilibrium exists between the production and decomposition of ozone molecules. Ozone layer depletion occurs when this balance of stratospheric ozone is tipped in favour of destruction.

15. Which of the following layer is not included in Homosphere? [Uttarakhand P.C.S. (Pre) 2021]

Correct Answer: (a) Ionosphere
Solution:Based on chemical composition, the atmosphere is divided into two broad layers; the homosphere and the heterosphere. The homosphere extends up to the height of 56 mi. (90 km.) and is characterised by uniformity in chemical composition.

It consists of three thermal layers, namely, the troposphere, the stratosphere, and the mesosphere. Each sub-layer is separated from the adjoining layer by a shallow transitional zone.

The heterosphere has heterogeneous chemical composition, with layered structure, of nitrogen, oxygen, helium, and hydrogen, respectively.

Generally, the atmosphere consists of five layers, namely, the troposphere, the stratosphere, the mesosphere, the thermosphere, and the exosphere.

The thickness of these layers is slightly different around the globe, and also varies with respect to temperature and season.

9.png

16. In stratosphere, the level of ozone is naturally regulated by- [U.P.P.C.S. (Mains) 2016]

Correct Answer: (b) Nitrogen dioxide
Solution:The ozone layer in the stratosphere is naturally regulated by Nitrogen dioxide. The thickness of the ozone layer varies seasonally. Its thickness is highest during spring and lowest during rain.

The measurement unit of the ozone layer is 'Dobson Unit' (DU). 1 DU is equal to 0.01 mm thickness of pure ozone at 0°C temperature and 1 am pressure.

17. Which of the following is not true about chlorofluorocarbon? [U.P. Lower Sub. (Pre) 2004]

Correct Answer: (b) Is not responsible for the greenhouse effect.
Solution:Chloroflurocarbon (CFC), any of several organic compounds composed of Carbon, fluorine and Chlorine. One of the elements that make CFC is chlorine.

Under certain conditions, this chlorine has the potential to destroy a large amount of ozone. Hence it is one of the major causes of the greenhouse effect.

18. Which one of the following is not correctly matched? [U.P.P.C.S. (Pre) 2017]

Green House GasSource
(a) Carbon dioxideThermal Power Stations
(b) ChlorofluorocarbonAutomobile
(c) Nitrous OxideWaterlogged Paddy fields
(d) Sulphur dioxideBrick Kilns

 

Correct Answer: (b)
Solution:Chlorofluorocarbon is a man-made gaseous and liquified material made from carbon, chlorine, fluorine and oxygen which is used as a refrigerant in refrigerators and air- conditioning devices. Chlorofluoro Carbon is an important factor of ozone depletion in the atmosphere.

Chlorofluorocarbons are used in a variety of applications because of their low toxicity, reactivity and flammability. Every permutation of fluorine, chlorine and hydrogen-based on methane and ethane has been examined and most have been commercialized.

19. Which is responsible for Ozone Hole? [Chhattisgarh P.C.S.(Pre) 2014]

Correct Answer: (d) CFC
Solution:CFC is responsible for the ozone hole. However, the atmospheric impacts of CFCs are not limited to their role as ozone-depleting chemicals. Infrared absorption bands prevent heat at that wavelength from escaping the earth's atmosphere. CFCs have their strongest absorption bands from C-F and C-Cl bonds in the spectral region of 7.8-15.3 µm-referred to as "atmospheric window" due to the relative transparency of the atmosphere within this region.

The strength of CFC absorption bands and the unique susceptibility of the atmosphere at wavelengths where CFCs (indeed all covalent fluorine compounds) absorb creates a "super" greenhouse gas (GHG) effect from CFCs and other unreactive fluorine-containing gases such as perfluorocarbons, HFCS, HCFCs, bromofluorocarbons.

20. The ozone hole is caused by: [U.P.P.C.S. (Pre) 2016]

Correct Answer: (c) Chlorofluorocarbons
Solution:Ozone depletion occurs when chlorofluorocarbons (CFC) are released into the atmosphere. These gases, through several chemical reactions, cause the ozone molecules to break down, reducing ozone's ultraviolet radiation absorbing capacity.

Acetylene is a hydrocarbon with the chemical formula C₂H₂. While it is a greenhouse gas, it is not considered a significant contributor to ozone depletion.

Ethylene is another hydrocarbon (C₂H₄) with similar properties to acetylene. It is also a greenhouse gas but not a major cause of ozone depletion.

Methane (CH₄) is a potent greenhouse gas, contributing significantly to global warming. However, it does not directly destroy ozone molecules in the same way that CFCs do. While methane can indirectly contribute to ozone depletion by enhancing other greenhouse gases' effects, its primary role is in climate change.