Which of the following statements is/are correct? 1. The Earth's crust is brittle in nature. 2. The mean thickness of the oceanic crust is 15 km, whereas that of the continental crust is around 30 km. Select the correct answer using the code given below.
- A.1 only
- B.2 only
- C.Both 1 and 2
- D.Neither 1 nor 2
Correct answer
Explanation
The correct answer is A, 1 only. The crust is brittle, but the mean thickness of the oceanic crust is about 5 km, not 15 km.
The crust is the outermost solid shell of the Earth. It is brittle, which is why it breaks along faults and produces earthquakes. Its thickness varies a great deal: under the oceans it averages about 5 km, while the continental crust averages about 30 km and is much thicker, up to about 70 km, under great mountain systems such as the Himalaya. Oceanic crust is mainly basalt and denser; continental crust is mainly granite and lighter.
B is wrong because statement 2 gives the oceanic figure as 15 km, three times the real mean. C is wrong because statement 2 is false. D is wrong because statement 1 is true.
Exam tip: oceanic crust about 5 km, continental crust about 30 km, up to 70 km under the Himalaya.
Practice Questions
View allWhere is Hambantota Port located?
- A.Iran
- B.Sri Lanka
- C.Japan
- D.Pakistan
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Hambantota Port lies on the southern coast of Sri Lanka, close to the main shipping lanes of the Indian Ocean.
Read the full explanation →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.
- A.2 only
- B.1 and 3 only
- C.2 and 3 only
- D.1, 2 and 3
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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.
Read the full explanation →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.
- A.1 and 2 only
- B.1 and 3 only
- C.2 and 3 only
- D.1, 2 and 3
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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.
Read the full explanation →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.
- A.1 only
- B.2 and 3
- C.1, 2 and 4
- D.2 and 4 only
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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.
Read the full explanation →Damanganga Reservoir Project with about 115 km of minor canals and distributaries is located in
- A.NCT
- B.Dadra and Nagar Haveli
- C.Puducherry
- D.Goa
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The Damanganga Reservoir Project is the main irrigation scheme of Dadra and Nagar Haveli, whose canal network of about 115 km of minor canals and distributaries serves the territory.
Read the full explanation →