What is the greenhouse effect?

When the Earth’s surface is heated upon by the radiations from the Earth, it results in increased temperature than is generally required, this process is known as the greenhouse effect. Most of the greenhouse gases are responsible to cause the greenhouse effect by radiating energy in all directions. The earth’s surface absorbs most part of this radiation that results in its warming. The strength of this effect depends upon the atmosphere’s temperature and the number of greenhouse gases present in the atmosphere. The primary greenhouse gases known are water vapour (H2O), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and ozone (O3). This paragraph has answered the question- What is a greenhouse effect short answer?

The article further discusses the several multiple-choice questions to develop a better understanding of the concept. The MCQs provided in the article aim to help students to prepare for their competitive examinations. 

Ideas for MCQs on Greenhouse Effect

Let’s go through the following MCQs on the greenhouse effect which is asked in most of the entrance examinations. Students can get an idea with the below questions and answers on the greenhouse effect.

1. Which One of the Following Is Not a Greenhouse Gas?

(a) Methane

(b) Hydrogen

(c) Nitrous oxide

(d) Ozone

Answer: (b)

Explanation-  methane, carbon dioxide, nitrous oxide and water vapour are the primary greenhouse gases that contribute to the greenhouse effect. A greenhouse gas (GHG or GhG) is a gas that absorbs and emits radiant energy in the thermal infrared spectrum, resulting in the greenhouse effect.

2. Which of the Following Have Higher Energy Levels and Shorter Wavelengths?

(a) Infrared radiation

(b) Ultraviolet radiation

(c) Beta radiation

(d) Alpha radiation 

Answer: (b)

Explanation- The UV radiation has a range of 100-400 nm, the UV that particularly has high energy is categorised in the wavelength of 100-200 nm.

3. Normal Greenhouse Effect Is Important for the Sustenance of Life on Earth as it Has Increased the Earth’s Surface Temperature By

(a) 15 ℃

(b) 50 ℃

(c) – 18 ℃

(d) 33 ℃

Answer: (d)

Explanation- The greenhouse effect is a natural phenomenon that keeps the earth at the temperature required for life to thrive. The remaining radiation, roughly half of it, reaches the planet and is absorbed by seas and land. This keeps the ground warm and provides food for plants, animals, and humans.

4. Infrared Radiations Have ----------------Wavelength?

(a) Shorter

(b) Infinite

(c) Longer

(d) Zero

Answer: (c)

Explanation-  The section of the electromagnetic spectrum that stretches from the long wavelength, or red, end of the visible-light range to the microwave range is known as infrared radiation. Near-infrared, medium infrared, and far-infrared are the three areas of the infrared spectrum.

5. Which of the Following Greenhouse Gases Is Present in Very High Quantities?

(a) Carbon dioxide

(b) Ethane

(c) Propane

(d) Methane

Answer: (a)

Explanation- Carbon dioxide has the highest concentration among the greenhouse gases, the concentration ranges from 9 to 26%, another important gas methane constitutes about 4 to 9% whereas ozone constitutes about 3 to 7%

6. Gas Molecules That Absorb Thermal Infrared Radiation and Are Present in Large Quantity to Alter the Climate System Is Known As

(a) Greenhouse gases 

(b) Beta radiations

(c) Alpha radiations

(d) Ozone gases

Answer: (a)

Explanation- Greenhouse gases are mainly responsible for trapping the thermal radiations, this entrapment leads to an overall increase in the temperature of the earth. 

7. Burning of Fossil Fuels Results In

(a) Increased oxygen level

(b) Decreases greenhouse gases

(c) Increased greenhouse gases

(d) Increased ethane level

Answer: c

Explanation- When fossil fuels are burnt, massive volumes of carbon dioxide, a greenhouse gas, are released into the atmosphere. Global warming is caused by greenhouse gases, which trap heat in our atmosphere.

8. the Most Potent Greenhouse Gas in Terms of Efficiency Is

(a) N2O

(b) C2O

(c) CFC 

(d) CH4

Answer: (c)

Explanation- CFC stands for chloro-fluoro carbons, these gases are primarily responsible for the ozone layer depletion, additionally they also trap heat in the atmosphere thus contributing to the greenhouse effect.

9. Which One of the Following Is Incorrect About the Greenhouse Effect?

(a) Life on earth is possible due to the greenhouse effect

(b) Greenhouse effect is a natural process that maintains the earth’s temperature

(c) More is the emission of greenhouse gases, more is the temperature of the earth’s atmosphere

(d) Increased emission of greenhouse gases is a natural process

Answer: (d)

Explanation- Increased emission of greenhouse gases is not a natural process, it rather occurs due to increased industrial activities. 

10. Which is Not Naturally Occurring Greenhouse Gas?

(a) Nitrous oxide

(b) Methane

(c) Carbon dioxide

(d) Ethane 

Answer: (d)

Explanation- Ethane is found at very low concentrations thus does not significantly contribute to the greenhouse effects, rather the conversion of ethane to methane largely contributes to the greenhouse effects. 

11. Which is Not True for the Relative Contribution of Various Greenhouse Gases to Total Global Warming?

(a) CFCs – 14%

(b) Carbon dioxide – 60%

(c) N₂O – 12%

(d) Methane – 20%

Answer: (c) 

Explanation- N2O – 12%, All the mentioned gases are contributors to global warming, but the relative global warming potential of N2O  is 6 percent. Relative global warming potential is the measurement of the amount of heat trapped in the atmosphere by a greenhouse gas over a specific period of time relative to CO2.


12. the GWP is Dependent on Which of the Following Factors?

a) Absorption capability of InfraRed radiations

b) Atmospheric lifetime

c) Range of Infrared wavelengths it can absorb

d) All of the above

Answer: (d)

Explanation- The heat absorbed by any greenhouse gas in the atmosphere as a multiple of the heat absorbed by the same quantity of carbon dioxide is referred to as global warming potential. All the factors are contributors to the GWP.

13. Which of the Following Greenhouse Gases Has the Highest Atmospheric Lifetime?

a) CFC

b) Nitrous oxide

c) Methane

d) Carbon tetrafluoride

Answer: (d)

Explanation- It is extremely stable, with a 50,000-year atmospheric lifespan, and a 6,500-fold higher greenhouse warming potential than CO2.

14. Which of the Following Has the Highest Radiative Efficiency?

a) Sulphur hexafluoride

b) Carbon tetrachloride

c) CFC


Answer: (d)

Explanation- Radiative efficiency is the term used to define the strength of the greenhouse gases, it can be better defined as the change in radiative forcing per change in the atmospheric concentration of a gas. The unit of it is Wm-2 ppb-1. A single molecule of PFTBA has the equivalent climate impact as 7100 molecules of carbon dioxide. 

15. Which Among the Following Compounds Have the Highest Gwp?

a) Nitrous oxide

b) Sulphur hexafluoride

c) Water vapour

d) CFC

Answer: (b)

Explanation- Sulphur hexafluoride is the most powerful greenhouse gas studied by the Intergovernmental Panel on Climate Change, having a global warming potential 22,200 times that of CO2 over a 100-year period. As the gas is exhaled, it accumulates in the atmosphere for many centuries in an almost undamaged condition.

16. Anthropogenic Sources of Carbon Dioxide Are 20 Times More Than Natural Carbon Dioxide Sources.

a) True

b) False

Answer: (b)

Explanation -CO2 emissions from power generation, transportation, industrial sources, chemical manufacture, petroleum production, and agricultural operations are all examples of anthropogenic CO2 emissions. Many of these sources emit CO2 as a consequence of burning fossil fuels (coal, oil, and natural gas). 

17. Why Is There an Extreme Difference in Temperatures at Day and Night in Deserts?

a) Carbon dioxide is present in low concentrations in desert regions, and thus heat escapes easily

b) Sand has high heat conduction properties

c) There’s lack of moisture leads to escape of heat

d) All of the above 

Answer: (c)

Explanation- Whenever the sun's heat and light strike a dry desert, the granules in the upper layer absorb and emit heat into the air. During the day, the sun's energy is radiated by sand, which superheats the air and causes temperatures to rise. However, because there is no sunshine to reheat the air at night, much of the heat in the sand soon radiates into the air, rendering the desert and its environment colder.

18. What Does the Method of “Enhanced Weathering” Mean?

a) Spraying sulphate aerosols to reduce the greenhouse effect

b) Cloud seeding is done to reduce the contribution of clouds to the greenhouse effect

c) Removing Carbon dioxide from the air

d) None of the above

Answer: (d)

Explanation- Weathering that is expedited by spreading finely powdered silicate rock, such as basalt, over land or water is known as enhanced weathering. This accelerates the chemical processes that remove carbon dioxide from the atmosphere and permanently deposit it as solid carbonate minerals or ocean alkalinity.

19. What is Carbon Sequestration?

a) Removal of CO2 from the atmosphere

b) Storage of CO2 by depositing in the reservoir

c) Removal of CO2 from the atmosphere & Storing it by depositing it in the reservoir

d) None of the above

Answer: (c)

Explanation- The method of trapping and storing atmospheric carbon dioxide is known as carbon sequestration. It is one way of lowering carbon dioxide levels in the atmosphere with the purpose of slowing global warming. The USGS is assessing two key kinds of carbon sequestration: geology and biological sequestration.

20. Which is a sink for carbon?

a) Saline water bodies

b) Old oil fields

c) Wetlands

d) All of the above

Answer: (d)

Explanation- All of the sources mentioned above act as a storage site for carbon dioxide.

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FAQs on MCQs on Greenhouse Effect

1.What are factors that affect greenhouse effects?

The overall energy input, which is dependent on the planet's distance from the sun and solar activity; the chemical composition of the atmosphere; and albedo, the capacity of the earth's surface to reflect light, are the three primary elements that directly impact the energy balance of the world.

2. What is the primary cause of the increase in greenhouse gases?

The amount of greenhouse gases in the atmosphere is increasing as a result of human activity, mostly carbon dioxide from the combustion of fossil fuels such as coal, oil, and natural gas. The excess greenhouse gas causes retention of heat that leads to an increase in the global temperature.

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