Question 1. What do you
understand by Green House Gases?
Answer.
Carbon dioxide fails in the atmosphere and causes the greenhouse effect by
stopping the heat evolved from the earth on the earth, due to which it is
called green house gas. In the absence of greenhouse gas, the earth would
become very cold and it would be impossible to live on it so it is a very
essential gas.
Question 2. State the
importance of nitrogen gas.
Answer.
Nitrogen is the most abundant gas in the air. The amount of nitrogen in the air
is about 78%. When we breathe, we also take nitrogen gas inside our lungs but
then send it back. Nitrogen gas is of great importance for plants, it is
related to their life. Plants cannot take nitrogen directly from the air, so the
bacteria living in the soil and the roots of some plants take nitrogen from the
air and change its form so that the plants can use it.
Question 3. Give three
examples of human environment.
Answer. Man
interacts with his environment and changes it according to his needs. In human
environment we can mainly place agriculture, animal husbandry, industry etc.
Question 4. Give 3
examples of man made environment.
Answer.
Such environment is called man-made environment which is created by man. Three
major examples of man-made environment are as follows -
1. Roads
and Bridges.
2. Parks
and Industries.
3. Building
and monument.
Question 5. Explain the
land revenue policy during Allauddin Khalji?
Answer.
Alauddin Khilji was such a sultan of Delhi who had developed a very excellent
land revenue system, some of its main features were as follows -
1. During
the reign of Alauddin Khilji, the state brought the work of land revenue and
recovery under its control.
2. The
right to levy taxes was taken away from the local feudatories, but they
themselves were also forced to pay taxes.
3. Alauddin
Khilji measured the land and kept its account very carefully.
4. The old
feudal lords and zamindars took up the job of the sultanate as revenue
assessment and recovery officers.
5. Alauddin
Khilji imposed three types of taxes -
(a) Agricultural
Tax - The tax levied on agriculture was called Kharaj and it was about 50% of
the farmer's produce.
(b) Cattle
tax.
(c) Taxes
on houses.
Question 6. What do you
understand by ecosystem?
Answer. Ecosystem - All
trees, plants, animals and humans are dependent on the environment around them
and are also dependent on each other. This relationship between the living
beings and their surrounding environment forms the ecosystem. Forests with high
rainfall, grasslands, deserts, mountains, lakes, rivers, oceans and small ponds
can also have their own ecosystem.
Question 7. What is the
lithosphere and what is its importance?
Answer.
Lithosphere - The solid crust or hard upper layer of the Earth is called the
lithosphere. It is made up of rocks and minerals and is covered by a thin layer
of soil. There is a heterogeneous surface with various landforms like
mountains, plateaus, plains, valleys etc. Apart from the continents, these
topographies are also found on the surface of the ocean.
The
lithosphere provides us with forests, land for agriculture and human
settlements, grasslands for grazing animals. It is also a storehouse of mineral
wealth.
Question 8. What do you
understand by natural environment?
Answer.
Land, water, air, trees, plants and animals together make up the natural
environment.
Question 9. What do you
understand by global warming?
Answer. On
Earth, when the level of carbon dioxide in the atmosphere starts increasing due
to the smoke of factories and car and when it increases the temperature of the
earth through heat, it is called global warming. Due to increase in
temperature, the ice frozen in the coldest region of the earth starts melting
and as a result the sea level starts rising and due to this the climate of the
world also changes, as a result of which some fauna and flora can become
extinct.
Question 10. What is the
importance of carbon dioxide?
Answer.
Carbon dioxide is another important gas. Green plants use carbon dioxide as
their food and give back oxygen. Due to carbon dioxide, the living temperature
on the earth is maintained.
Question 11. What do you
understand by stratosphere?
Answer. The
upper part of the troposphere is called the stratosphere. It extends to a
height of about 50 km. This layer is almost free from clouds and meteorological
phenomena, as a result of which the conditions here are ideal for flying
airplanes. An important feature of the stratosphere is that it contains a layer
of ozone gas, this layer protects us from harmful gases coming from the sun.
Question 12. What is the
composition of the atmosphere?
Answer. Our
atmosphere is divided into 5 layers which start from the surface of the earth.
These are as follows troposphere, stratosphere, mesosphere, outer atmosphere
and outer atmosphere.
Question 13. What is the
policy of sulh-e-kul?
Answer.
Akbar treated people of all religions as equal and made a policy in which all
religions were respected and all good ideas were considered. The main objective
of this policy was to promote peace and fraternity and to end intolerance.
Question 14. What was the
effect of the Mongol invasion on the Delhi Sultanate?
Answer. The
Mongols under the leadership of Genghis Khan also attacked the Delhi Sultanate
and to avoid this attack, the rulers of the Delhi Sultanate had to keep a huge
army so that the situation of war could be dealt with. Alauddin Khilji's force
was on defense while the steps taken by Muhammad Tughluq were part of a plan of
military offensive against the Mongols.
Q15. What do you
understand by constituency?
Answer. A
constituency is a fixed area where all the voters residing in the constituency
choose their representatives. For example, it can be a ward of a Panchayat or
an area from which a member of the Legislative Assembly is elected.