Class 11 Geography: The Earth — Chapter Question Set

(c) 4.6 billion years — This is the textbook-supported choice for the question.

(b) Differentiation — This is the textbook-supported choice for the question.

(d) 3.8 billion — This is the textbook-supported choice for the question.

b) us since the childhood — The textbook states: Starry nights have always attracted us since the childhood.

a) questions in your mind — The textbook states: You may also have thought of these stars and had numerous questions in your mind.

d) there in the sky? — The textbook states: Questions such as how many stars are there in the sky?

c) still there in your mind — The textbook states: May be many more such questions are still there in your mind.

b) formed — The textbook states: In this chapter , you will learn how these “twinkling little stars” were formed.

a) evolution of the earth — The textbook states: With that you will eventually also read the story of origin and evolution of the earth.

d) Earth — The textbook states: EARLY THEORIES Origin of the Earth A large number of hypotheses were put forth by different philosophers and scientists regarding the origin of the earth.

c) German — The textbook states: One of the earlier and popular arguments was by German philosopher Immanuel Kant.

b) formed out of a cloud of material associated — The textbook states: The hypothesis considered that the planets were formed out of a cloud of material associated with a youthful sun, which was slowly rotating.

a) 1950 — The textbook states: In 1950, Otto Schmidt in Russia and Carl W eizascar in Ger many somewhat revised the ‘nebular hypothesis’, though differing in details.

d) surrounded by solar nebula containing mostly — The textbook states: They considered that the sun was surrounded by solar nebula containing mostly the hydrogen and helium along with what may be termed as dust.

c) THE ORIGIN AND EVOLUTION — The textbook states: The friction and collision of particles led to formation of a disk-shaped cloud and the planets were THE ORIGIN AND EVOLUTION OF THE EARTH CHAPTER formed through the process of accretion.

b) earth or the planets — The textbook states: However, scientists in later period took up the problems of origin of universe rather than that of just the earth or the planets.

a) Universe The — The textbook states: MODERN THEORIES Origin of the Universe The most popular argument regarding the origin of the universe is the Big Bang Theory.

d) 1920 — The textbook states: Edwin Hubble, in 1920, provided evidence that the universe is expanding.

c) further and further apart — The textbook states: As time passes, galaxies move further and further apart.

b) the expanding universe mean — The textbook states: Y ou can experiment and find what does the expanding universe mean.

a) to represent the galaxies — The textbook states: Take a balloon and mark some points on it to represent the galaxies.

d) as the balloon expands — The textbook states: Now, if you start inflating the balloon, the points marked on the balloon will appear to be moving away from each other as the balloon expands.

c) also found to be increasing and thereby — The textbook states: Similarly, the distance between the galaxies is also found to be increasing and thereby, the universe is considered to be expanding.

b) expanding — The textbook states: However, you will find that besides the increase in the distances between the points on the balloon, the points themselves are expanding.

a) increasing — The textbook states: Scientists believe that though the space between the galaxies is increasing, observations do not support the expansion of galaxies.

d) only partially correct — The textbook states: So, the balloon example is only partially correct.

c) development of the universe — The textbook states: The Big Bang Theory considers the following stages in the development of the universe.

b) Big Bang — The textbook states: (ii) At the Big Bang the “tiny ball” exploded violently.

a) 13.7 billion — The textbook states: It is now generally accepted that the event of big bang took place 13.7 billion years before the present.

d) to the present day — The textbook states: The expansion continues even to the present day.

c) converted into matter — The textbook states: As it grew, some energy was converted into matter.

b) particularly rapid expansion within fractions — The textbook states: There was particularly rapid expansion within fractions of a second after the bang.

a) Big Bang — The textbook states: Within first three minutes from the Big Bang event, the first atom began to form.

d) 300,000 years — The textbook states: (iii) Within 300,000 years from the Big Bang, temperature dropped to 4,500 K (Kelvin) and gave rise to atomic matter.

c) space between the galaxies — The textbook states: The expansion of universe means increase in space between the galaxies.

b) Hoyle — The textbook states: An alternative to this was Hoyle’s concept of steady state.

a) any point of time — The textbook states: It considered the universe to be roughly the same at any point of time.

d) argument of expanding universe — The textbook states: However , with greater evidence becoming available about the expanding universe, scientific community at present favours argument of expanding universe.

c) not even in the early universe — The textbook states: The Star Formation The distribution of matter and energy was not even in the early universe.

b) get drawn together — The textbook states: These initial density differences gave rise to differences in g ravitational forces and it caused the matter to get drawn together .

a) for development of galaxies — The textbook states: These for med the bases for development of galaxies.

d) measured in thousands of light-year s — The textbook states: Galaxies spread over vast distances that are measured in thousands of light-year s.

c) 80,000 — The textbook states: The diameters of individual galaxies range from 80,000-150,000 light years.

b) nebula — The textbook states: A galaxy starts to form by accumulation of hydrogen gas in the form of a very large cloud called nebula.

a) localised clumps of gas — The textbook states: Eventually, growing nebula develops localised clumps of gas.

d) to formation of stars — The textbook states: These clumps continue to grow into even denser gaseous bodies, giving rise to formation of stars.

c) 6 billion — The textbook states: The formation of stars is believed to have taken place some 5-6 billion years ago.

b) 300,000 km — The textbook states: Light travels at a speed of 300,000 km/second.

a) taken to be one light year — The textbook states: Considering this, the distances the light will travel in one year is taken to be one light year .

d) 149,598 — The textbook states: The mean distance between the sun and the earth is 149,598,000 km.

The friction and collision of particles led to formation of a disk-shaped cloud and the planets were THE ORIGIN AND EVOLUTION OF THE EARTH CHAPTER formed through the process of accretion. These small-rounded objects by the process of cohesion develop into what is called planetesimals . It is through the process of differentiation that the earth forming material got separated into different layers.

E EE EEVOLUTIONVOLUTIONVOLUTIONVOLUTIONVOLUTION OF OFOFOFOF THE THETHE THETHE E E E E E ARTH ARTHARTH ARTHARTH Do you know that the planet earth initially was a barren, rocky and hot object with a thin atmosphere of hydrogen and helium. From the surface to deeper depths, the earth’s interior has different zones and each of these contains materials with different characteristics. This allowed heavier materials (like iron) to sink towards the centre of the earth and the lighter ones to move towards the surface.

With that you will eventually also read the story of origin and evolution of the earth. The friction and collision of particles led to formation of a disk-shaped cloud and the planets were THE ORIGIN AND EVOLUTION OF THE EARTH CHAPTER formed through the process of accretion. Singularity THE ORIGIN AND EVOLUTION OF THE EAR TH 15 (ii) In the next stage, the gas cloud starts getting condensed and the matter around the core develops into smallrounded objects.

Starry nights have always attracted us since the childhood.

You may also have thought of these stars and had numerous questions in your mind.

Questions such as how many stars are there in the sky?

May be many more such questions are still there in your mind.

In this chapter , you will learn how these “twinkling little stars” were formed.

With that you will eventually also read the story of origin and evolution of the earth.

EARLY THEORIES Origin of the Earth A large number of hypotheses were put forth by different philosophers and scientists regarding the origin of the earth.

One of the earlier and popular arguments was by German philosopher Immanuel Kant.

The hypothesis considered that the planets were formed out of a cloud of material associated with a youthful sun, which was slowly rotating.

In 1950, Otto Schmidt in Russia and Carl W eizascar in Ger many somewhat revised the ‘nebular hypothesis’, though differing in details.

They considered that the sun was surrounded by solar nebula containing mostly the hydrogen and helium along with what may be termed as dust.

The friction and collision of particles led to formation of a disk-shaped cloud and the planets were THE ORIGIN AND EVOLUTION OF THE EARTH CHAPTER formed through the process of accretion.

However, scientists in later period took up the problems of origin of universe rather than that of just the earth or the planets.

MODERN THEORIES Origin of the Universe The most popular argument regarding the origin of the universe is the Big Bang Theory.

It is also called expanding universe hypothesis.

Edwin Hubble, in 1920, provided evidence that the universe is expanding.

As time passes, galaxies move further and further apart.

Y ou can experiment and find what does the expanding universe mean.

Take a balloon and mark some points on it to represent the galaxies.

Now, if you start inflating the balloon, the points marked on the balloon will appear to be moving away from each other as the balloon expands.

Similarly, the distance between the galaxies is also found to be increasing and thereby, the universe is considered to be expanding.

However, you will find that besides the increase in the distances between the points on the balloon, the points themselves are expanding.

MODERN THEORIES Origin of the Universe The most popular argument regarding the origin of the universe is the Big Bang Theory. The Big Bang Theory considers the following stages in the development of the universe. (ii) At the Big Bang the “tiny ball” exploded violently. It is now generally accepted that the event of big bang took place 13.7 billion years before the present. There was particularly rapid expansion within fractions of a second after the bang. Within first three minutes from the Big Bang event, the first atom began to form. (iii) Within 300,000 years from the Big Bang, temperature dropped to 4,500 K (Kelvin) and gave rise to atomic matter.

With that you will eventually also read the story of origin and evolution of the earth. The friction and collision of particles led to formation of a disk-shaped cloud and the planets were THE ORIGIN AND EVOLUTION OF THE EARTH CHAPTER formed through the process of accretion. Singularity THE ORIGIN AND EVOLUTION OF THE EAR TH 15 (ii) In the next stage, the gas cloud starts getting condensed and the matter around the core develops into smallrounded objects. From the surface to deeper depths, the earth’s interior has different zones and each of these contains materials with different characteristics. Evolution of LithosphereEvolution of LithosphereEvolution of LithosphereEvolution of LithosphereEvolution of Lithosphere The earth was mostly in a volatile state during its primordial stage. Evolution of Atmosphere and HydrosphereEvolution of Atmosphere and HydrosphereEvolution of Atmosphere and HydrosphereEvolution of Atmosphere and HydrosphereEvolution of Atmosphere and Hydrosphere The present composition of earth’s atmosphere is chiefly contributed by nitrogen and oxygen. In the second stage, the hot interior of the earth contributed to the evolution of the atmosphere.

Starry nights have always attracted us since the childhood. Starry nights have always attracted us since the childhood. You may also have thought of these stars and had numerous questions in your mind. Questions such as how many stars are there in the sky?

You may also have thought of these stars and had numerous questions in your mind. Starry nights have always attracted us since the childhood. You may also have thought of these stars and had numerous questions in your mind. Questions such as how many stars are there in the sky? May be many more such questions are still there in your mind.

Questions such as how many stars are there in the sky? You may also have thought of these stars and had numerous questions in your mind. Questions such as how many stars are there in the sky? May be many more such questions are still there in your mind. In this chapter , you will learn how these “twinkling little stars” were formed.

May be many more such questions are still there in your mind. Questions such as how many stars are there in the sky? May be many more such questions are still there in your mind. In this chapter , you will learn how these “twinkling little stars” were formed. With that you will eventually also read the story of origin and evolution of the earth.

In this chapter , you will learn how these “twinkling little stars” were formed. May be many more such questions are still there in your mind. In this chapter , you will learn how these “twinkling little stars” were formed. With that you will eventually also read the story of origin and evolution of the earth. EARLY THEORIES Origin of the Earth A large number of hypotheses were put forth by different philosophers and scientists regarding the origin of the earth.