With reference to the formation of stars, consider the following statements: 1. A galaxy starts to form by the accumulation of helium gas in the form of a nebula. 2. The initial density differences in the early universe gave rise to differences in gravitational forces. 3. The formation of stars is believed to have taken place about 13.7 billion years ago. Which of the statements given above is/are correct?

Correct Option The correct option is 2 only Explanation The formation of stars and galaxies is rooted in the evolution of the early universe following the Big Bang. The uneven distribution of matter and energy in the early universe created the gravitational conditions necessary for the accumulation of gas and the subsequent birth of celestial bodies. Statement-wise Analysis - Statement 1 is Incorrect: In the early universe, the distribution of matter and energy was not even. These initial density differences gave rise to differences in gravitational forces. These forces caused matter to get drawn together, forming the basis for the development of galaxies. - Statement 2 is Correct: A galaxy starts to form by the accumulation of hydrogen gas (not helium) in the form of a very large cloud called a nebula. While helium was present in the early universe, hydrogen is the primary element involved in the formation of nebulae and subsequent star formation. - Statement 3 is Incorrect: The event believed to have taken place about 13.7 billion years ago is the Big Bang. The formation of stars is believed to have taken place much later, approximately 5 to 6 billion years ago. Key Takeaway Key Takeaway: The Big Bang occurred 13.7 billion years ago, while star formation began around 5-6 billion years ago. Nebulae, the birthplaces of stars, are primarily composed of hydrogen gas.

With reference to the formation of stars,… - NCERT Class 11 Geography MCQ

NCERT Class 11 Geography — Chapter 1: The Orgin and Evolution of the earth

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With reference to the formation of stars, consider the following statements:

A galaxy starts to form by the accumulation of helium gas in the form of a nebula.
The initial density differences in the early universe gave rise to differences in gravitational forces.
The formation of stars is believed to have taken place about 13.7 billion years ago.

Which of the statements given above is/are correct?

NCERT textbook question

From NCERT Fundamentals of Physical Geography · Page 3

Options

A2 only
B1 and 3 only
C1, 2 and 3
D1 only

Did you get this right?

Solution

Correct Option

The correct option is

2 only

Explanation

The formation of stars and galaxies is rooted in the evolution of the early universe following the Big Bang. The uneven distribution of matter and energy in the early universe created the gravitational conditions necessary for the accumulation of gas and the subsequent birth of celestial bodies.

Statement-wise Analysis

Statement 1 is Incorrect: In the early universe, the distribution of matter and energy was not even. These initial density differences gave rise to differences in gravitational forces. These forces caused matter to get drawn together, forming the basis for the development of galaxies.
Statement 2 is Correct: A galaxy starts to form by the accumulation of hydrogen gas (not helium) in the form of a very large cloud called a nebula. While helium was present in the early universe, hydrogen is the primary element involved in the formation of nebulae and subsequent star formation.
Statement 3 is Incorrect: The event believed to have taken place about 13.7 billion years ago is the Big Bang. The formation of stars is believed to have taken place much later, approximately 5 to 6 billion years ago.

Key Takeaway

Key Takeaway: The Big Bang occurred 13.7 billion years ago, while star formation began around 5-6 billion years ago. Nebulae, the birthplaces of stars, are primarily composed of hydrogen gas.

Your note

More from Chapter 1: The Orgin and Evolution of the earth

The "Nebular Hypothesis" is primarily associated with the origin of which of the following?

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In the revised Nebular Hypothesis proposed by Schmidt and Weizsäcker, the solar nebula was considered to be primarily composed of:

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Which of the following theories regarding the origin and evolution of the universe is currently most accepted by the scientific community?

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The "Giant Impact" hypothesis primarily explains the origin of which celestial body?

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Through which process do planetesimals aggregate to form larger planetary bodies?

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