Subject : General Science Teacher: Mr Ehtisham Ul Haq Class: BS EDUCATION Semester: 2nd (Spring(2023-2027) Date Of Starting Of Semester : 4 September 2023 Date Of End Of Semester : 20 January 2024 University Of Sargodha Institute of Education These are the presentation slides that we prepare by our own research and work!

1. GENERAL SCIENCE
SUBMITTED TO : SIR EHTISHAM UL HAQ
SUBMITTED BY
GROUP MEMBERS :
MEHAK NOOR (ROLL NO.10)
ALIZA MOHSAN (ROLL NO.13)
HARAM FATIMA (ROLL NO .15)
BISSAM (Leader) (ROLL NO.25)
NADIA RIAZ (ROLL NO .30)
DEPARTMENT: BS EDUCATION
SESSION: 2023-2027

2. TOPIC:
CHAPTER NO. 7
ENERGY

3.  What is Work and Energy?
 Explain Different forms of Energy?
 Discuss Demand of Energy?
 Explain Production of Electrical Energy?
 Elaborate Measurement of Energy?
 Explain Energy and the Environment?
 Discuss Degradation of Environment?

4. In general work is defined as:
Any activity that requires muscular or mental effort
is called work.
According to science work is defined as:
Work is the product of force and distance in the
direction of force.
Work=Force*Distance
Unit of work is Joule.
Named in honour of the 19th century English Physicist
James Prescott Joule.

5. Defination of 1 joule:
Workdone is said to be one joule when force of 1 netwon
displaces the object through displacement of 1m.
1J=1Nm
Examples of Work done:

6. Energy is defined as:
The ability to do work is called energy.
UNIT OF ENERGY:
Since the unit for work is joule therefore , the
unit for energy is also joule(J).

7.  Kinetic Energy.
 Potential Energy.
 Elastic Potential Energy.
 Chemical Energy.
 Heat Energy.
 Light Energy.
 Electrical Energy.
 Nuclear Energy.

8. Energy possessed by a body due to its motion is known as
kinetic energy (K.E). It depends on the mass and speed
of a body .More the mass or speed of a body more is the
K.E.

9. Energy possessed by a body due to its position is known
as potential energy.
It is determined by the following 3 factors :
 Mass of the body.
 Acceleration due to
gravity.
 Height of the body.

10. The energy stored in a body by pressing, stretching,
or twisting is known as elastic potential energy.

11. The energy stored in the bonds of atoms and molecules
is called chemical energy .In cells and batteries ,
chemical energy transforms into electrical energy. The
energy obtained by our bodies by consuming food is
also chemical energy.

12. Heat energy is due to the movement of the molecules of
bodies. The faster the movement of molecules, the
greater is the heat energy. Sun is its largest source.

13. Light is a form of energy. When electrons revolving
around the nucleus jump from a higher energy orbit to a
lower energy orbit, light is emitted. Light is also needed
for photosynthesis process.

14. It is the energy of moving charges. Electrical energy can
be transformed into different forms of energy.

15. It is obtained by the nuclei of heavy atoms .The process
is called nuclear fission. This process is done in a
nuclear reactor where energy is released in the form of
heat. Energy is also released when the nuclei of small
atoms fuse together. This is known as nuclear fusion.

16. About 50 years ago, there was no electricity. At the
same time , there was no concept of refrigerator and
television. With the advancement of science, people got
many comforts of life. In many fields of life , the
consumptions of energy is still increasing.

17. We use energy in the form of heat, light and molten etc ,
but the most important use of energy is in the form of
electrical energy.
There are 2 methods of production of electricity :
1. Traditional methods.
2. Non traditional methods.
Some of the traditional and non traditional sources of
producing electricity are as follows:

18. Hydroelectric power:
The conversion of K.E of running water to electrical energy
is called hydro electrical power. Water is stored in a lake or
a reservoir. At a height, gravitational potential energy is
stored in the water. When water fall from height the
potential energy is changed into kinetic energy.

19. Thermal power:
Guddu Thermal Power Station is located in Sindh,
Pakistan .In this method , coal , oil and natural gas are
burnt .These are known as fossil fuels. It will take
million of years to form new fuels once the old ones are
exhausted. Chemical potential energy is stored in fossil
fuels. The burning of those fuels helps the turbine to
produce electricity.

20. Nuclear power:
In Pakistan there are nuclear power plants at Karachi and
Chashma. Pakistan's first Nuclear Power Plant,
KANUPP (Karachi Nuclear Power Plant ) Unit 1 was
constructed in Karachi and achieved its first criticality on
1st August, 1971. The source of nuclear energy is the
nucleus of an atom in which energy is stored. Uranium
235 or Plutonium is used as fuel.

21. Solar power:
The energy which is obtained from sun is called solar
energy. The solar energy falling on the atmosphere of
earth is almost 1.4 kilowatt per square meter.
Solar energy is used in 2 ways :
 In one way solar panels absorb heat.
 In second method, sunlight is directly transformed to
electricity with the help of solar cells.

22. How does a calculator use solar energy?
The mechanism behind solar calculators is fascinating. It
works through photovoltaic technology that converts light
energy into direct electrical energy. The solar cell captures
the energy, which flows through the internal circuits of the
calculator, powering its operations. Usually, the solar cell
consists of two layers of silicon-based semiconductor
material. An average calculator consumes around 0.02 -
0.35 watts of solar power.

23. EXAMPLE OF SOLAR POWER:

24. Wind power:
In wind power ,K.E of fast blowing air is used to produce
electricity. A wind mill consists of three or four wings
mounted on a top of a pole .These are called turbines of
wind mill. Traditional wind mill is used to grind grains and
to fetch water from the well. Modern wind mill is used to
run generators that produce electricity.

25. Tidal power:
Big tides of water are generated in the sea due to attraction
of moon. The energy of those tides is known as tidal
energy. The tidal energy can be used to produce electricity.

26. To make use of energy deep under the Earth in the form
of hot water or stream is known as geothermal. The
stream is used to run generators, through which
electricity is produced.

27. Biomass is a natural source of energy. It consists of all
organic materials such as (residue of crops, trees, plants,
vegetables). Organic materials and their residues are
called biomass.

28. Energy:
Ability to do work. The SI unit of work and energy is
joule.
Measuring electrical energy:
Practically kilowatt-hour unit is used for its
measurement. The energy consumed in one second is
called power.
Power =Energy/Time
The unit of power is watt. One thousand watt power is
called as one kilowatt.

29. UNIT OF ELECTRICAL ENERGY:
The unit of electrical energy is kilowatt-hour ,denoted
as kwh.
One kilowatt hour is the amount of energy that is
consumed by a 1000 watt appliance in one hour.

30. The working principle of a meter is same as that of
electric motor. Live wire of main supply passes through
the field coils of the meter .The coil is connected to the
main supply through a high resistance. When current
starts flowing , it produces a magnetic field due to which
the coil inside the field rotates. Usually the digit to the
extreme right is 1/10th of the unit i.e decimal point.

31. Natural gas is measured in cubic meters. The gas turns a
wheel while passing through its way . Al-through petrol,
diesel and natural gas are measured in unit of volume but
these fuels can also be measured in units of energy. These
days , gas bills are being charged on the base of Btu instead
of cubic meters. The Btu is a unit of energy called the
British Thermal Unit. One Btu is equal to 1055 joules.

32. ENVIRONMENT:
The living place of people and all physical and social
factors that affect their living and working conditions is
called environment.
COMPONENTS OF ENVIRONMENT:
Air , water and land . Air is present upto the height of
about 200 km from the surface of Earth.It is called
atmosphere. The part of atmosphere where all living
bodies reside in is about 8 to 20 km thick cover of gases
over the Earth

33. LAYERS OF
ATMOSPHERE:
 The Troposphere.
 The Stratosphere.
 The Mesosphere.
 The Thermosphere.

34. The pollution caused in the environment by heat, smoke
and harmful gases is called thermal pollution. Heat is
very essential for plants, animals and human beings.
FACTORS Of THERMAL POLLUTION:
There are many factors that cause thermal pollution:
1. Carbon dioxide, Carbon monoxide, Sulphur dioxide,
lead compounds and other harmful gases in addition.
2. Fossil fuels are burnt in transport.
3. Nuclear energy used for producing electricity.

35. Natural thermal pollution does not affect the
environment badly.
When pollution more than a certain limit is added to the
environment, it is known as degradation of
environment.
Industries consume almost 20% of energy resources.
Such energy sources should be promoted , which
produce less pollution e.g , electrical energy, solar
energy, wind energy, tidal energy.