RBSE Class 11 Geography Important Questions Chapter 2 The Origin and Evolution of the Earth

Rajasthan Board RBSE Class 11 Geography Important Questions Chapter 2 The Origin and Evolution of the Earth Important Questions and Answers. 

RBSE Class 11 Geography Important Questions Chapter 2 The Origin and Evolution of the Earth

Multiple Choice Questions

1. How many years ago did the moon originate?
(A) 2.44 billion years
(B) 4.44 billion years
(C) 3.44 billion years
(D) 5.44 billion years.
Answer:
(B) 4.44 billion years

 

2. Who introduced the big bang theory?
(A) Laplace
(B) Edwin Hubbal
(C) Newton
(D) Molton.
Answer:
(B) Edwin Hubbal

3. The universal principle regarding the origin of earth is
(A) Nebula
(B) Bigbang 
(C) Tidal
(D) Bilateral.
Answer:
(B) Bigbang 

4. The solar system is a Hellio-centric system who believed it?
(A) Aristotle
(B) Arya Bhatt
(C) Arab Scholars
(D) Chinese Scholars.
Answer:
(B) Arya Bhatt

5. How many planets are there is Solar system?
(A) 6 
(B) 7
(C) 8 
(D) 8.
Answer:
(C) 8 

6. Which is the inner planet?
(A) Earth
(B) Jupiter
(C) Saturn
(D) Naptune.
Answer:
(A) Earth

7. To which country did Emanuel Kant belong?
(A) India
(B) France
(C) England
(D) Germany.
Answer:
(D) Germany.

8. When did Leplace presented Nabular Theory?
(A) 1795 
(B) 1796
(C) 1797
(D) 1798.
Answer:
(B) 1796

9. Which force separated gaseous material from sun?
(A) Gravitational force
(B) Friction
(C) Angular momentum
(D) Centrifugal force.
Answer:
(A) Gravitational force

10. Which gas converted to Helium?
(A) Hydrogen
(B) Nitrogen
(C) Oxygen
(D) Argon.
Answer:
(A) Hydrogen

 

Very Short Answer Type Questions

Question 1. 
Name a philosopher who believed that the earth was at the centre of the universe.
Answer: 
Aristotle-a Greek Philosopher.

Question 2. 
What was meant by Geocentric Theory?
Answer: 
It meant that the moon, sun, planets and stars orbited around earth.

Question 3. 
What is Helio-centric Solar System?
Answer: 
The sun is the centre of solar system. All the planets, stars moved around the sun.

Question 4. 
Name an Indian Scientist who believed in Helio-Centric System.
Answer: 
Aryabhatta.

Question 5. 
How many planets are there in Solar System?
Answer: 
Eight.

Question 6. 
Name the inner planets.
Answer: 
Mercury, Venus, Earth and Mars.

Question 7. 
Name the outer planets.
Answer: 
Jupiter, Saturn, Uranus and Neptune.

Question 8. 
Name the unique planet where life exists.
Answer: 
Earth.

Question 9. 
Who forwarded the Nebula Hypothesis?
Answer: 
German Philosopher Immanuel Kant and Laplace.

Question 10. 
Who forwarded the collision Hypo¬thesis?
Answer: 
Sir James Jeans and Harold Jeffreys.

Question 11.
What was the shape of tongue of matter ejected from sun?
Answer: 
Cigar shaped.

Question 12. 
What do you mean by Supernova?
Answer: 
A star million times brighter than the sun.

Question 13. 
Which scientist of Russia modified the Nebular Hypothesis and in which year?
Answer: 
Otto Schmidt in 1950.

Question 14. 
Which is the Hypothesis of Jeans and Jeffreys?
Answer: 
Binary Hypothesis.

Question 15. 
Which is the most popular theory regarding the origin of the Universe?
Answer: 
Big Bang Theory.

Question 16. 
How much distance is travelled by light in a light year?
Answer: 
9.461 x 1012 km.

Question 17. 
What gave the concept of steady state?
Answer: Hoyle. 

Short Answer Type Questions

Question 1. 
What do you mean by a Tight year’?
Answer: 
A light year is a measure of distance and not of time. Light travels at a speed of 300,000 km/second. Considering this, the distance the light will travel in one year is taken to be one light year. This equals to 9.461 x 1012 km. The mean distance between the Sun and the Earth is 149,598,000 km. In terms of light years, it is 8.311 minutes.

 

Question 2. 
What is Solar System? When was it formed?
Answer: 
Our Solar System. Our Solar system consists of eight planets. The nebula from which our Solar system is supposed to have been formed started its collapse and core formation sometimes 5 to 5.6 billion years ago and the planets were formed by about 4.6 to 4.56 billion years ago. Our Solar system consists of the Sun, 8 planets, 173 moons, millions of smaller bodies like asteroids and comets and huge quantity of dust grains and gases.

Question 3. 
How were oceans originated?
Answer: 
Carbon dioxide in the atmosphere got dissolved in rainwater and the temperature further decreased causing more condensation and more rains. The rainwater falling on to the surface got collected in the depressions to give rise to oceAnswer: The earth’s oceans were formed within 500 million years from the formation of the earth. This tells us that the oceans are as old as 400 million years.

Question 4. 
Describe the different stages in the evolution of present day atmosphere.
Answer: 
There are three stages in the evolution of the present atmosphere. The first stage is marked by the loss of primordial atmosphere. In the second stage the hot interior of the earth contributed to the evolution of the atmosphere. Finally, the composition of atmosphere  was modified by the living world through the process of photosynthesis.

Question 5. 
(i) What is a Nebula?
Answer: 
Nebula is a slowly rotating cloud of Gases. It contains hot gaseous matter of dust-gas clouds.

(ii) What are planetesimals?
Answer: 
Due to collision of the sun and passing star, a filament of gaseous material was pulled away from the pre-existing sun. This filament (tongue-shaped) was broken into small chunks which went flying as cold bodies. These are called planetesimals.

(iii) Who first proposed Nebular Hypothesis?
Answer: 
The Nebular Hypothesis was first proposed by German Philosopher Immanuel Kant in 1755.

(iv) What is a Protostar?
Answer: 
The Nebula of hot gaseous cloud exploded to form a Supernova. Its denser portions collapsed under their own gravity. The dense core became larger and hotter. It is called Protostar it finally became the infant sun.

Question 6. 
Describe the modification proposed in Nebular Hypothesis by Otto Schmidt. 
Answer: 
In 1950 Otto Schmidt in Russia and Carl Weizascar in Germany 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 alongwith what may be termed dust. The friction and collision of particles led to formation of a disc shaped cloud and the planets were formed through the process of accretion.

Question 7. 
Describe the process of Star Formation.
Answer: 
The Star Formation. The distribution of matter and energy was not even in the early Universe. These initial density differences gave rise to difference in gravitational forces and it caused the matter to get drawn together. These formed the basis for development of galaxies. The galaxies contain a large number of stars. They spread over vast distances, to be measured in thousands of light-years. These range in size with diameters ranging from 80,000 to 150,000 light years.

A galaxy starts to form by accumulation of hydrogen gas in a very large cloud called nebula. Eventually growing nebula develops localised clumps of gas, which continue to grow into even denser gaseous bodies giving rise to formation of stars. The formation of stars is believed to have taken place some time 5 to 6 billion years ago.

Question 8. 
Compare the inner planets and outer planets.
Answer: 
Of the eight planets Mercury, Venus, Earth and Mars are called as inner planets as they lie between the Sun and the belt of asteroids called the asteroid belt. The other four plants, lining up after the asteroid belt are Jupiter, Saturn, Uranus and Neptune are called outer planets. Alternatively the first four are called ‘Terrestrial’, meaning Earth like, as they are made up of rock and metals and have relatively high densities. The rest four are called Jovian or Gas Giant planets. Jovian means Jupiter like. Most of them are much larger than the terrestrial planets and have a thick atmosphere mostly of helium and hydrogen. All the planets were formed in the same period, some time about 4.6 billion years ago. 

Question 9. 
Describe a comparative analysis of planets as regards distance from the sun, density, radius and satellites.
Answer:
The Solar System

	Mercury	Venus	Earth	Mars	Jupiter	Saturn	Uranus	Neptune
Distance *	0.387	0.723	1.000	1.524	5.203	9.523	19.208	30.087
Density	5.44	5.24	5.517	3.945	1.33	0.70	1.28	1.66
Radius #	2440	6052	6378	3397	71492	60268	25559	24766
Satellites	o	o	1	2	67	62	27	14

*Distance in astronomical unit i.e. average mean distance of the earth is 149,598,000 km = 1 
@ Density gm/cm3
#Radius - in km 

Question 10. 
Explain the formation of Moon.
Answer: 
The Moon: The Moon is the only natural satellite of the Earth. Like origin of the earth there have been attempts to explain how the moon was formed. In 1838 Sir George Darwin (son of Charles Darwin) suggested that initially the earth and the moon formed a single rapidly rotating body. The whole mass became a dumbbell shaped body and eventually it broke. It was also suggested that the material forming the Moon was separated from what we have at present the depression occupied by Pacific Ocean. However, the present scientists do not accept either of the explanations. 

It is now generally believed that the formation of Moon as a satellite of the earth is an outcome of ‘giant impact’ or what is described as “the big splat”. A body of the size of 1-3 times Mars slammed into the earth sometime shortly after the earth was formed. It blasted a large part of the earth into space. This portion of blasted material then continued to orbit the earth and eventually formed into the present Moon. This event or formation of the moon is supposed to have taken place at least 4.44 billion years ago. Almost about 0.15 billion years after the planet earth was formed.

Question 11. 
How did life originate on the earth? 
Answer: 
Modern scientists refer to the origin of life as a kind of chemical reactions, which first generated complex organic molecules and assembled them. This assemblage was such that they could duplicate themselves converting inanimate matter into living substance. The record of life that existed on this planet in different periods is found in rocks in the form of fossils. The microscopic structures closely related to the present form of blue algae have been found in geological formations that are much older than some 3000 million years. It can be assumed that simpler forms precede these. Scientists consider that the life began to evolve sometime 3800 million years ago.

Essay Type Questions

Question 1. 
Describe the Nebular Hypothesis regarding the origin of the Planets.
Answer:
Nebular Hypothesis. Some Monistic Theories (One Star Theories) explain the origin of planets. A German Philosopher, Immanuel Kant, proposed the Nebular Hypothesis. This Hypothesis was based on Newton’s Laws of motion.
Outlines of Hypothesis:

1. According to Kant, the primordial matter was scattered in the space.
2. This matter was supernaturally created.
3. There was a slowly rotating cloud of gas called Nebula.
4. The original cold and motionless Nebula became a hot and spinning Nebula under the gravitational attraction. The French mathematician, Laplace proposed more or less, same theory in 1796.
5. The rotational speed increased under Law of conservation of angular momentum. The centrifugal force then increased.
6. Thus, successive rings of gaseous matter were thrown off from the central mass (Equator) by centrifugal force.
7. The rings later on condensed to form planets. The residual central mass remained as the sun.

Criticism:

1. It was the forerunner of Laplace theory.
2. Heat and motion cannot be produced in cold Nebula without some external force.
3. Kant, despite criticism went to say “Give me matter and I can create the earth. ”

Question 2.
Describe the collision Hypothesis proposed by Sir James Jeans and Sir Harold Jeffreys. 
Answer: 
This theory belongs to Dualistic (Two Stars) Theories. This theory was forwarded by British scientists Sir James Jeans and Sir Harold Jeffreys in 1926. According to this theory, planets are bi-parental in origin. It is also known as Tidal Hypothesis.

Outline of Hypothesis:

1. The sun was originally a very hot gaseous mass in the space.
2. Another star, several times bigger than the sun came close to the sun and caused Tidal disruptions.
3. Due to gravitational pull of the approaching star, gaseous material was pulled away from the pre-existing sun. The ejected matter, called Filament was cigar shaped.
4. This filament was broken into small chunks called planetesimals.
5. By collision and gravitational attraction the larger planetesimals collected the smaller bricks and condensed into planets.

Merits and Demerits:
It is the most accepted Hypothesis. The present arrangement of planets confirms this idea. The number of satellites also proves the theory. The smaller planets have less satellites. But this theory fails to explain the location of the planet Mars. The temperature of the Sun is too high for the formation of planets.

Source Based Questions

1. Read the following paragraph and answer the questions given below:
The Big Bang theory is the most popular argument regarding the origin of the universe. This is also known as Expanding Universe Hypothesis. In 1920, Edwin Hubble provided evidence that the universe is expanding. As the time passes, galaxies also move further and further. You can find and experiment what does the expanding universe mean. To represent the galaxies, take a balloon and mark some points on it. If you start inflating a balloon, points that you mark on the balloon will appear to be moving away from each other. Similarly, the distance between two galaxies is also found to be increasing when the universe is expanding. Scientists believe that though the space between the galaxies is increasing, observations do not support the expansion of galaxies.

(i) Which theory is the most popular regarding the universe origin?
(a) Big Bang 
(b) Pulsating
(c) Plate tectonics 
(d) All of these 
Answer: 
(a) Big Bang

(ii) Who provided Big Bang theory?
(a) Edwin Hubble 
(b) Moulten
(c) Kant 
(d) Laplace
Answer: 
(a) Edwin Hubble

(iii) In which year big bang theory was introduced?
(a) 1928 
(b) 1820
(c) 1920 
(d) 1925
Answer: 
(c) 1920

(iv) According to the Big Bang theory universe is-
(a) Shrinking 
(b) Expanding
(c) Moving 
(d) Both 
Answer: 
(b) Expanding

2. Read the following paragraph and answer the questions given below:
The moon is the only natural satellite of the earth. Like origin of the earth, there have been attempts to explain how the moon was formed. In 1838, Sir George Darwin suggested that initially the earth and the Moon formed a single rapidly rotating body. The whole mass become a dumb¬bell shaped body and eventually it broke. It was also suggested that the material forming the moon was separated from what we have at present the depression occupied by Pacific Ocean. However, the present scientists do not accept either of the explanation. 

It is now generally believed that the formation of moon as a satellite of the Earth is an outcome of giant impact or what is described as the big splat. A body of the size of 1-3 times Mars slammed into the earth sometime shortly after the earth was formed. It blasted a large part of the earth into space, about 0.15 billion years after the planet earth was formed.

(i) Which is a natural satellite of earth?
(a) Ganymede 
(b) Titan
(c) Moon 
(d) Phobos
Answer: 
(c) Moon

(ii) Who suggested that initially earth and moon formed a single rapidly rotating body?
(a) George Darwin 
(b) Charles Darwin 
(c) Charles David 
(d) Emma Darwin
Answer:
(a) George Darwin

(iii) A large part of earth blasted out into the space billion years after the earth was formed.
(a) 0.1 
(b) 0.2
(c) 0.15 
(d) 0.5
Answer: 
(c) 0.15 

HOTS QUESTIONS 

Question 1
Differentiate between Terrestrial and Jovian planets. 
Answer:

Terrestrial	Jovian
1. These were formed close vicinity of the parent star.	1. These are formed at quite a distant location.
2. From the terrestrial planets solar wind was intense nearer to the sun. Lots of gas and dust blow by it.	2. From the jovian planets solar winds were not all that intense to cause same removal of gases.
3. These are smaller planets.	3. These are larger than terrestrial planets.

SELF EVALUATION TEST

1. How many planets are there in solar system?
2. Who forwarded the Nebula Hypothesis? 
3. How much distance is travelled by light in a year? 
4. Which are inner planets? 
5. What do you mean by supernova?
6. Name the outer planets. 
7. What is Solar System? 
8. What is a Nebula? 
9. What are planetesimals? 
10. Describe the Nebular Hypothesis regarding the origin of planets.