With reference to the crust of the Earth, consider the following statements: 1. The mean thickness of the oceanic crust is around 50 km. 2. The continental crust is thicker than the oceanic crust. 3. The continental crust thickness never exceeds 30 km. Which of the statements given above is/are correct?

The correct option is 2 only Explanation The crust is the outermost solid part of the Earth. It is brittle in nature and varies significantly in thickness and composition depending on whether it is oceanic or continental. Statement-wise Analysis: - Statement 1 is Incorrect: The continental crust is significantly thicker than the oceanic crust. The mean thickness of the continental crust is approximately 30 km, whereas the oceanic crust is much thinner. - Statement 2 is Correct: The mean thickness of the oceanic crust is approximately 5 km, not 50 km. It is denser and thinner compared to the continental crust. - Statement 3 is Incorrect: The thickness of the continental crust varies depending on the topography. While the mean thickness is around 30 km, it can be much thicker in areas of major mountain systems. For instance, in the Himalayan region, the thickness of the crust can reach up to 70 km. Key Takeaway: Oceanic crust is thin (approx. 5 km) and dense (basaltic), whereas continental crust is thick (approx. 30 km, reaching 70 km in mountains) and less dense (granitic).

With reference to the crust of the… - NCERT Class 11 Geography MCQ

NCERT Class 11 Geography — Chapter 2: Interior of the earth

mcqeasy

With reference to the crust of the Earth, consider the following statements:

The mean thickness of the oceanic crust is around 50 km.
The continental crust is thicker than the oceanic crust.
The continental crust thickness never exceeds 30 km.

Which of the statements given above is/are correct?

NCERT textbook question

From NCERT Fundamentals of Physical Geography · Page 22

Options

A1 and 3 only
B1 only
C1, 2 and 3
D2 only

Did you get this right?

Solution

The correct option is

2 only

Explanation

The crust is the outermost solid part of the Earth. It is brittle in nature and varies significantly in thickness and composition depending on whether it is oceanic or continental.

Statement-wise Analysis:

Statement 1 is Incorrect: The continental crust is significantly thicker than the oceanic crust. The mean thickness of the continental crust is approximately 30 km, whereas the oceanic crust is much thinner.
Statement 2 is Correct: The mean thickness of the oceanic crust is approximately 5 km, not 50 km. It is denser and thinner compared to the continental crust.
Statement 3 is Incorrect: The thickness of the continental crust varies depending on the topography. While the mean thickness is around 30 km, it can be much thicker in areas of major mountain systems. For instance, in the Himalayan region, the thickness of the crust can reach up to 70 km.

Key Takeaway:

Oceanic crust is thin (approx. 5 km) and dense (basaltic), whereas continental crust is thick (approx. 30 km, reaching 70 km in mountains) and less dense (granitic).

Your note

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