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GeographyEasyAsked in: CTET · Paper II SST, 21 Jan 2024

Which of the following two gases make up the bulk of the Atmosphere?

  1. A.Ozone and Helium
  2. B.Nitrogen and Hydrogen
  3. C.Carbon dioxide and Oxygen
  4. D.Nitrogen and Oxygen

Correct answer

D. Nitrogen and Oxygen

Explanation

The correct answer is D, Nitrogen and Oxygen. Together these two gases make up about 99 percent of the air around the Earth. Nitrogen alone is about 78 percent of the atmosphere and oxygen about 21 percent. The remaining 1 percent is mostly argon, with very small amounts of carbon dioxide, helium, ozone, hydrogen and water vapour. NCERT's Class 7 geography book puts it in one line: nitrogen and oxygen are the two gases that make up the bulk of the atmosphere. Plants need nitrogen to grow, and all living things need oxygen to breathe. A is wrong because ozone and helium are found only in tiny amounts, though ozone shields us from ultraviolet rays. B is wrong because hydrogen, unlike nitrogen, is present only in traces in the air. C is wrong because carbon dioxide is a very small share of the air, even though it traps heat and matters for climate. Exam tip: nitrogen about 78 percent, oxygen about 21 percent, argon about 0.93 percent.

Practice Questions

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Q2.GeographyAsked in: CDS · CDS-II 2017, GKMedium

Which of the following statements is/are correct? 1. Himalayan rivers have their origin in the snow-covered areas, hence are dry in winter season. 2. Rivers of the Peninsular Plateau have reached maturity. 3. Himalayan rivers depict all the three stages of normal cycle of erosion. Select the correct answer using the code given below.

  1. A.2 only
  2. B.1 and 3 only
  3. C.2 and 3 only
  4. D.1, 2 and 3
Show answer
Correct answer: C. 2 and 3 only

Himalayan rivers are perennial, so statement 1 is wrong, while statements 2 and 3 are correct. Himalayan rivers such as the Ganga, Indus and Brahmaputra rise from glaciers and snowfields and also get monsoon rain, so they flow all year round, including in winter.

Q3.GeographyAsked in: CDS · CDS-II 2017, GKMedium

Which of the following statements related to latitude are true? 1. Rainfall, temperature and vegetation vary with latitude. 2. The difference between the longest day and the shortest day increases with latitude. 3. Indira Point is located approximately at 6°45' N latitude. Select the correct answer using the code given below.

  1. A.1 and 2 only
  2. B.1 and 3 only
  3. C.2 and 3 only
  4. D.1, 2 and 3
Show answer
Correct answer: D. 1, 2 and 3

All three statements about latitude are true. Latitude decides how directly the Sun's rays strike a place, so temperature, rainfall and the type of vegetation change from the equator towards the poles, from hot, wet rainforests to cold tundra.

Q4.GeographyAsked in: CDS · CDS-II 2017, GKMedium

Which of the following lakes is/are situated in Ladakh? 1. Tso Kar 2. Pangong Tso 3. Tsomgo 4. Tso Moriri Select the correct answer using the code given below.

  1. A.1 only
  2. B.2 and 3
  3. C.1, 2 and 4
  4. D.2 and 4 only
Show answer
Correct answer: C. 1, 2 and 4

Tso Kar, Pangong Tso and Tso Moriri are high-altitude lakes of Ladakh, while Tsomgo lies in Sikkim. Pangong Tso, at about 4,350 metres, is a long, narrow lake that stretches from Ladakh into Tibet, and most of its length lies on the Chinese side.