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GeographyEasyAsked in: NDA · NDA-I 2023, GAT

Which one of the following is not an igneous rock?

  1. A.Granite
  2. B.Slate
  3. C.Basalt
  4. D.Gabbro

Correct answer

B. Slate

Explanation

The correct answer is B, Slate. Slate is a metamorphic rock, formed when shale is changed by heat and pressure.

Igneous rocks form when molten magma or lava cools and hardens. If it cools slowly deep underground, the crystals grow large and we get intrusive rocks like granite and gabbro; if it cools quickly on the surface, we get fine-grained extrusive rocks like basalt. Slate starts as shale, a sedimentary rock made of clay, and is then squeezed and heated inside the crust until it becomes hard and splits into thin, flat sheets, which is why it was used for roofs and writing slates.

A is wrong: granite is a coarse-grained intrusive igneous rock.

C is wrong: basalt is an extrusive igneous rock; the Deccan Traps are made of it.

D is wrong: gabbro is an intrusive igneous rock, the slow-cooled cousin of basalt.

Exam tip: shale becomes slate, limestone becomes marble, sandstone becomes quartzite, granite becomes gneiss.

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.