Energy and Power Resources

Solutions for Geography, Class 7, ICSE

Answer in brief

7 questions

Question 4(a)

Give three ways to save energy.

Answer in brief

Answer:

Three ways to save energy are:

Energy can be conserved by reducing wastage and losses, improving efficiency through technological upgrades and improved operation and maintenance.
Use of LED bulbs, turning off light when not in use, unplugging computers and turning off televisions can help us reduce our daily consumption of energy at home.
Carpooling and use of public transport helps to save fuel/energy.

Question 4(b)

State any three advantages of solar power.

Answer in brief

Answer:

Advantages of Solar Energy:

Solar energy is a sustainable resource of energy.
Solar power does not cause any pollution.
Solar panels require little maintenance and can be easily installed.

Question 4(c)

State any three uses of biogas.

Answer in brief

Answer:

Uses of biogas:

It is commonly used in rural areas as cooking gas.
It can be used for the production of electricity.
It can be used for water heating and space (room) heating etc.

Question 4(d)

Why should we conserve coal and petroleum?

Answer in brief

Answer:

Coal and petroleum are exhaustible or non-renewable source of energy. They are limited in supply. If they are not used judiciously, they will not last for more than a few decades. Therefore, it is very important to conserve these fuels.

Question 4(e)

Why do we grow trees around the industries?

Answer in brief

Answer:

Industries cause pollution. Growing trees around industries helps to reduce pollution and purify the air. Trees also help in reducing the sound pollution caused by industries.

Question 4(f)

What is the significance of Bhakra Nangal Project?

Answer in brief

Answer:

Significance of Bhakra Nangal project:

It provides electricity for industrial, agricultural and domestic use.
This project has helped in controlling floods in the river Sutlej downstream.
It also helps in soil conservation, afforestation and development of fish culture.
It benefits many industries like textile, cotton, sugar etc.

Question 4(g)

Write a note on the advantages and disadvantages of multipurpose projects.

Answer in brief

Answer:

Advantages of multipurpose projects are:

Generation of hydroelectric power and thereby encourage the development of industries in the country.
Provision of irrigation where the rainfall is scanty.
Control of floods in the rivers.
Development of river navigation.
Afforestation for soil conservation.

Disadvantages of multipurpose projects:

Cost of building dams is very high.
Building large dams can cause serious geological damage like triggering earthquake in the area.
Dams alter the natural water table and have adverse impact on aquatic life.
Setting up of multipurpose projects displaces many people from the area causing them hardships.

Exercise

2 questions

Question 2

Fill in the blanks:

(a) Fossil fuel are found in ............... rocks.

(b) Coal is a ............... power resource.

(d) Solar energy is ............... source of energy.

(e) Coal is a ............... source of energy.

Exercise

Answer:

(a) Fossil fuel are found in sedimentary rocks.

(b) Coal is a non-renewable power resource.

(d) Solar energy is renewable source of energy.

(e) Coal is a non-renewable source of energy.

Question 3

Differentiate between

(a) Renewable and non-renewable sources of power.

(b) Solar and wind energy

Exercise

Answer:

(a) Differences between renewable and non-renewable sources of power:

S. No.	Renewable source of power	Non-renewable source of power
1.	Renewable energy resources can be used again and again.	Non-renewable energy resources cannot be used again and again.
2.	These are the energy resources which cannot get exhausted.	After some years it will get exhausted.
3.	It has low carbon emission and hence environment friendly.	It has high carbon emission and hence not environment friendly.
4.	Renewable energy resources are pollution free.	The non-renewable energy resources are not pollution free.
5.	It has high maintenance cost.	It has low maintenance cost.
6.	Solar energy, wind energy, tidal energy are some examples of renewable resources.	Coal, petroleum, natural gases are some examples of non-renewable resources.

(b) Differences between solar and wind energy:

S. No.	Solar energy	Wind energy
1.	Sun is the source of solar energy.	Moving air i.e., wind is the source of wind energy.
2.	Solar panels are used to tap solar energy.	Wind mills or wind turbines are used to tap wind energy.
3.	Solar power is only available during the day.	Wind power is available even at night.
4.	Low maintenance.	High maintenance.