Occupation, Business and Technology 7

For audio-visual talk, we need web-cam or camera, head phone with micro
phone which make audio-visual talk possible. There are SKYPE, TALK-
BOX, SIGHT-SPEED, SPIKKO, PHONERLITE, MIRIAL SOFTPHONE,
HOMER, EYBALLCHAT, etc. People who are far away from home do
video chat and enjoy very much.

Activity and Exercise

1. What is the importance of computer in our life? Discuss and write.
2. Computer has brought radical change in every field.' Justify this statement
3. Modern life is not possible if computer stops working? Do you agree?

Give your opinion in the class and debate with your friends.
4. What is the importance of e-mail?
5. Describe the use of Internet.

Project Work
Bring the old sets of TV, radio, computer, FM radio and study the different
parts of these devices.

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Lesson

6

Alternative Energy

Teaching Learning Objectives
After the study of this lesson, students will be able:
• to name the sources of alternative energy and state their importance.

Pre-reading Activity
The sun is the unlimited and ultimate source of energy. Discuss.

Terms & Terminologies

alternative : a thing that you can choose to do or have out of two or
perpetual more possibilities or substitute
renewable
: continuous or everlasting
bio-gas : (of energy and natural resources) that is replaced
inevitable
fossil fuel naturally or controlled carefully and can therefore be
inevitable used without the risk of finishing it all
: especially methane, that is produced by dead plants and
that can be burned to produce heat
: that you cannot avoid or prevent
: fuel such as coal or oil, which was formed over millions
of years from the remains of animals or plants
: unavoidable, expected

A. Introduction

Energy is defined as the ability to work. When we eat food, it is converted
into energy and we work. Each and every activity is possible only by
energy. Animals, birds, insects, plants, etc. all need energy to survive.
All types of machines need energy to run. So energy is the life line of
all things. There are different sources of energy. They can be classified
into two groups: they are living sources of energy and non-living
sources of energy. When we get energy from different living things
such as animals, birds, plants, etc. It is called living source of energy.
When we eat meat, we get energy. When we eat food, we get energy.

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But, we are talking here about the natural sources of energy which are
being used such as petrol, gas, hydropower, coal, firewood, etc.
B. Types of Sources of Energy
There are two types of sources of energy on the basis of their existence.
i) Renewable or Perpetual Energy
ii) Non-renewable or Fixed Sources of Energy
i) Renewable or Perpetual Energy: It means those sources of energy

which remain forever and can be renewed again after being used.
These sources of energy are solar energy, wind, hydropower, forest,
etc. We get energy again and again from these sources. We can
plant trees and get new forest. The energy from the sun remains
until it exists. Renewable and perpetual sources of energy are the
foundations of future development when there will be no other
sources of energy.

ii) Non-renewable or Fixed Source of Energy: A non-renewable
source is a source that cannot be renewed after being used. These
sources of energy are limited in the earth. They are petrol, diesel,
kerosene, petroleum, gas, coal, etc.
They are called non-renewable sources of energy because they
can’t be remade and reproduced after being used once.

C. Needs and Importance of Alternative Sources of Energy
We know that the non-renewable sources of energy such as petrol,

gas, kerosene, diesel, etc. are going to finish from the earth. Modern
development is based on these fossil materials. But these sources are limited
in the earth. They cannot be produced again after their use. So, to continue
our development in the future, we need alternative sources of energy.

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Alternativesourcesofenergymeansthosesourceswhichcanbeusedinplace
of non-renewable sources of energy. These are mainly renewable sources
of energy. They are solar energy, wind energy, hydro-energy, bio-energy,
geo-thermal energy, nuclear energy, etc. These sources of energy can
be long lasting. Importance of alternative energy can be highlighted as
follows:

• Alternative sources of energy are solar energy, hydro energy, wind
energy, nuclear energy, bio-energy, geo-thermal energy, etc.

• They are permanent sources of energy and never finish.

• They are environmental friendly and environment can be saved
and maintained.

• They are the foundations of future development when all the
sources of fossil fuel will finish.

• Nepal can save lots of money if we use alternative sources of energy.

• We can carry out economic development easily by using alternative
sources of energy.

• These sources of energy can be used all over the country.

• Each and everyone can get benefit from alternative sources of energy.

D. Bio-gas

Bio-gas is the natural product of bacterial digestion of organic wastes.
It is produced by the breakdown of organic matter in the absence of
oxygen. It is a renewable energy source, like solar and wind energy. It is
50 to 65 per cent or more methane gas, which is a powerful greenhouse
gas when released into the atmosphere, but burnt as a fuel for cooking,
heating or even running a generator. It is cleaner than gasoline or wood.
Furthermore, bio-gas can be produced from regionally available raw
materials such as recycled waste such as manure, sewage, municipal
waste, green waste, plant material, and crops. It is environment friendly.
Bio-gas can be made either aerobically (in contact with the air) or an-
aerobically in a sealed chamber, which is the more common approach
as it makes collecting the gas simpler and avoids unpleasant odour. A
small-scale batch digester can be constructed for home use.

E. Importance of Bio-gas

i. Production of Energy: Bio-gas has a high energy value of around
6kWh/m3—this is equal to half a liter of diesel. It is cheap and easy.
It can be produced in different parts of the country. It is made from
the dung of animals such as cow, buffalo, donkey, ox, etc.

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ii. Good Source of Alternative Energy: Bio-gas is one of the most
important alternative sources of energy. It can be used in place of
kerosene, firewood, coal.

iii. Fertilizer: Bio-gas plants—can produce fertilizer from natural
organic waste. The nitrogen rich fertilizer is obtained by processing
cow dung. It contains high nitrogen which is three times higher
than for the fertilizer obtained by conventional methods.

iv. Reduction of Workload: The use of bio-gas can reduce workload in
rural areas. It is a quick, cheap and convenient method to produce
fertilizers for many people. It reduces the work load of the people.

v. Positive Health Effects: Bio-gas has a positive effect on rural health
conditions. Bio-gas plants help to decrease the occurrence of respiratory
diseases. A considerable decrease in the cases of asthma, eye infections
and lung diseases has been noted in areas where there have been
implementation of many bio-gas plants. These plants are also responsible
for killing pathogens, such as cholera, typhoid and paratyphoid.

vi. Environmental Benefits: Bio-gas plants considerably reduce the
greenhouse effects on the earth’s atmosphere by recycling waste. They
also protect many natural resources, as they work to prevent waste, as
well as provide a more environment friendly energy source.

vii. Protects Forest from Deforestation: Most of the people in Nepal
use fire wood to cook food. People collect firewood from the forests
and it leads to the destruction of forest. Due to bio-gas they don’t
need fire wood. They use bio-gas to cook food.

viii. Long Lasting, for 20-30 Years: Once the bio-gas plant is established,
it can work for a long time. It can easily run for up to 30 years.

ix. Improves Economic Standard of Villagers: The people who use
kerosene and fire wood suffer from different types of respiratory
diseases. People spend money for the treatment but with use of bio-
gas there is no problem of smoking which improves their health
and saves money which goes for treatment.

F. Method of making bio-gas

i. Foundation: The bio-gas plant is built within the surface of the earth
underground and it is on the foundation that the whole bio-gas plant
is based. The foundation forms the base of the digester where the
most important processes of bio-gas plant occur. The foundation base
of the digester is made up of cement concrete and brick ballast. The
construction should be built in such a manner that it should be able to

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provide stable foundation for the digester walls and be able to sustain
the full load of slurry filled in it. The foundation should be waterproof
so that there is no percolation and leakage of water.
ii. Digester: The digester is the most important part of the cow bio-gas
plant where all the important chemical processes or fermentation
of dung and production of bio-gas takes place. The digesters
sometimes are also called as fermentation tank.
iii. Dome: The hemispherical top portion of the digester is called dome.
The dome has a fixed height, where all the gas generated within the
digester is collected. The gas collected in the dome exerts pressure
on the slurry in the digester.
iv. Inlet Chamber: The cow dung is supplied to the digester of the bio-gas
plant via inlet chamber, which is made at the ground level so that the
dung can be poured easily. It has bell mouth sort of shape and is made
up of bricks, cement and sand. The outlet wall of the inlet chamber is
made inclined so that the dung easily flows to the digester.
v. Outlet Chamber: Through the outlet chamber the digested slurry
from which the bio-gas has been generated is removed from the
plant. A few steps are usually provided in the outlet chamber so
that some person can go into the pit and clean it. The opening of
the outlet chamber is also at the ground level. The slurry from the
outlet chamber flows to the pit made especially for this purpose.
vi. Mixer: It is the first part of the bio-gas generator, where the water
and cow dung are mixed together in the ratio of 1:1 to form the
slurry which is fed into the inlet chamber.
vii. Gas Outlet Pipe and Valve: The gas outlet pipe is located at the top of
the dome where the bio-gas produced in the digester is collected. The
flow of the gas through the dome via the gas pipe can be controlled by
valve. The gas taken from the pipe can be transferred to the point of use.

Look at the pictures of bio-gas plant.

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G. Windmill
A windmill is a structure or machine that converts wind into useable

electric energy through the rotation of a wheel made up of adjustable
blades. Traditionally, the energy produced by a windmill has been used
to grind grain into flour as well as to sail boats but at present windmill
has become a source of alternative energy. It has taken the place of fossil
fuel which is limited. It can be a reliable source of energy in the days to
come. There are two types of windmill. They are horizontal axis windmill
and vertical axis windmill.

H. Process of Establishing a Windmill
Finding a Site for the Windmill
We can’t establish windmill everywhere. It can be established where

there is significant pressure of wind. There is a need of flowing air at least
24km/hr to move the fan of the windmill. After the site selection, it must
be cleared from trees and other obstacles. Sometime a concrete tower or
mound is created to catch more wind.

I. Function
By its name also, it is clear that the windmill functions with the help of

flowing air. The wind rotates the fans of the mill. The moving fans help to
move the turbine. When the wind-turbine is moved, then the electricity is
produced. The electricity is used for different purposes.

J. Precautions
• For windmill, the selection of appropriate site is very important.
• It must be established where there is continuous high pressure of

wind.
• The moving blades or fans should not be touched.
• The wire also should not be touched because it can have electric

current.

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Activity and Exercise

1. What do you mean by alternative sources of energy? Discuss in the class.
2. What types of alternative sources of energy are being used in your

locality? Tell your friends.
3. What is the importance of alternative sources of energy?
4. What are the sources of alternative energy? Describe them.
5. ‘The sun is the ultimate source of all energy.’ Justify this statement.
6. Discuss and describe the importance of bio-gas.

Project Work

• Prepare a file describing the sources of alternative energy, their use and
their importance.

• Discuss the process of making bio-gas.
• Visit a bio-gas plant and a windmill and observe them and prepare a

report about your visit.

Points to Remember

Lesson-1 Use of Electricity for Domestic Purpose
m Electricity is a boon of modern technology.
m It is used to light house, area, to run different appliances such as

iron, fan, TV, radio, refrigerator, heater, cooler, etc.
m But electrical appliances should be used very wisely, otherwise

there is a risk of life and fire.
m We should not use and touch any wire with our bare hands and we

should not tamper with it.

Lesson-2 Modern Appliances of Domestic Use
m Modern technology has developed so many domestic appliances

which make our life comfortable and easy.
m They help us to work fast and comfortably.
m Micro oven, vacuum cleaner, juice maker, grinder, etc are some of

them which have made domestic work very easy.

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m Even though these appliances are very useful, they should be used
very carefully to prevent accidents.

Lesson-3 Introduction to Technology and Its Importance

m Science and technology has developed wonderful things which
were not imagined before few centuries.

m Aero-plane, train, jet, computer, telephone, mobile phone, internet,
electricity, atomic energy, etc. have brought revolution in the space,
thinking and way of life.

m Modern life now seems impossible without these modern
technologies.

Lesson-4 Process of Transmission of FM, Radio and Television

m TV, radio and FM are the greatest means of communication.

m These means are used as the source of information, entertainment,
education, knowledge, advertisement, etc.

m The process of trasmissions

Sound waves electronic waves into amplifier

into radio waves radio waves transmitter radio

Lesson-5 Computer as a Means of Communication

m Modern development of science has been fully dominated by the
computer.

m From a very small work to high level of research all are based on
computer.

m The traditional way of communication has totally changed due to
the development of internet.

m The vast world has been changed into small lap-top or palm-top.

Lesson-6 Alternative Energy

m Present development is based on fossil fuel which is limited and
inevitable to finish.

m The energy which is used in place of fossil fuel is called alternative
energy.

m Solar power, wind power, bio-gas, hydroelectricity etc are some of
the examples of alternative energy.

m Alternative sources of energy are everlasting and offer hope for the
future.

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Occupation, Business and Technology Education

Class-7 Specification Grid for Practical Exam

Full Marks: 50 Pass Marks: 20 Time: 1 Hour and 30 Minutes

SN Subject Area Units Activity No Marks Total Remarks
Marks

Professional Education Professional Education 1 5

Education, Training And 1 5
Employment

1. • Selection Of Profession And

Their Planning Process 1 5 Attempt All
• Information Related To The Activities
15

Employment

General Vocational /Soft Skills 1 5
Vocation
Business/Vocation Orientation Business And Market
Management

a. Vegetable Farming

b. Fruit Cultivation

c. Dry Vegetable ,Fruit, And
2. Food Stuff
Attempt Any
d. Floriculture And Medicinal
4 Activities
Plants 4 20
Out of 8
e. Care Of Animals And Birds
From a -h
f. Art And Crafts

g. Clay Work

h. Sewing, Knitting And

Painting

3. Technology Local Technology 1 Attempt All
Education Activities
Modern Technology 1

Total 1 50 50

A Guideline and Marks Distribution for 50 Marks of Practical Examination

SN Description Marks
1. Report Presentation By Inquiry 10
2. Record Of Practical Works 5
3. Construction Of Materials And Their Use 20
4. Mini Project Work(Development Of Draft Plan) 10
5. Oral Examination 5
50
Total Marks:

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Occupation, Business and Technology Education

Class-7 Specification Grid for Theoretical Exam

Full Marks: 50 Pass Marks: 20 Time: 1 Hour and 30 Minutes

SN Subject / Units No of Marks Knowledge/ Skill Higher Total Remarks
Area Questions Comprehension Ability Marks

Professional Education 1 5 1 5

Professional/ Education, Training and 1 5 15 Attempt all the questions
Vocational Education Employment 15

1.

• Selection of

Profession and their

Planning Process 15

• Information Related
to Employment

• General Vocational 1 5 15 Attempt all the
or Soft Skills questions

Orientation of Business/Vocation • Vocation

• Business
And Market
Management

a. Vegetable Farming

b. Fruit Cultivation Attempt Any 4 Questions Out Of 8 From a-h

c. Dry Vegetable, Fruit,
2. and Food Stuff

d. Floriculture and
Medicinal Plants

e. Rearing and Caring 4 20 1 2 1 20

of Animals and

Birds

f. Art and Crafts

g. Clay Work

h. Sewing, Knitting
and Painting

3. Technology Local Technology 15 1 5
Education 5
Modern Technology 15 1

Total 10 50 4 4 2 50

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A Set of Model Questions for Theoretical Exam

Occupation, Business and Technology Education

Full Marks: 50 Grade-7 Pass Marks: 20
Time: 1 Hour and 30 Minutes

Answer the following questions.

Group ‘A’ (3×5=15)

1. Define professional education and write its importance in four points.

2. What is training and how does it help to get employment? Explain.

3. Describe any five sources of information of employment.

Group ‘B’ (5×5=25)

Note: Answer any FIVE questions from Group ‘B’ but Question No. 4
is compulsory.

4. What things should be considered while selecting a business? Describe.

5. Describe the importance of off -seasonal vegetables in five points.

6. Name any five fruits which are found in your locality and write their
season of cultivation.

7. How is milk tea prepared? Write its instructions.

8. Write any five medicinal plants along with their one use of each plant.

9. What are the common symptoms found in poultry? Write any five.

10. Write the difference between origami and Kirigami art.

11. Write any five points of importance of clay work.

12. What is called decorative stitch? Write any four commonly used decorative
stitches.

Group ‘C’ (5×2=10)

13. Define and distinguish local and modern technologies with their
appropriate examples.

14. Define alternative energy and describe its importance in four points.

Best of Luck!

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