lesson from CBSE 10 Science text book

1. Sources of ENERGY

2. Law of conservation of energy
 Burning candle
 Freely falling body
 Cooling of hot water
(348K-278K)
 Energy in usable form is
dissipated to the surroundings in
less usable form

3.  large amount of energy per unit mass
 cheap and easily available
 easy to store and transport
 not cause any pollution
 GOOD FUEL
 has a high calorific value
 lowest ignition temperature
 be economical
 burns without giving out any smoke

4. CONVENTIONAL SOURCE OF ENERGY
Sources of energy in INDIA
COAL
PETROLEUM
HYDRO
NUCLEAR
WIND
 Fossil Fuels
* non-renewable
* limited reserves
* causes pollution
(oxides of C, N and S )
* affects water & soil
resources
* Energysourceswhichareusedtraditionallyformanyyearsandaretodepleteover
aperiodof timearecalled conventionalsources.
*Thefuels whichareobtained fromtheremainsof plantsandanimalsarecalled
fossilfuels.

5. GENERATING ELECTRICITY
Thermal Power Plant
Fossil fuels - Heat Energy - Mechanical Energy - Electrical Energy

6. BIOGAS
# slurry of cow-dung and water
# fed into oxygen free DIGESTER
# anaerobic micro-organisms decomposes
the slurry , generates CH4 (75%),CO2,H2
and H2S
# burns without smoke - no residue
# slurry left used as manure (N2-P4)
*Themixtureof gaseswhichis obtainedby thedecompositionof animal andplantwastewiththe help
micro- organismsin thepresenceof water

7. WIND ENERGY
~ Eco friendly, renewable
~ a large fan erected at ht.
~ Wind speed must be
15kmph.
~ K.E to M.E then to E.E
~ No. of mills are joined
together to form W.E farm.
~ Denmark is called the
country of winds (25%)
~ Germany is the leader
~ India has 5thrank(45KMW)
~ WE farm nr Kanyakumari
generates 380MW
The blowing wind has energy which is associated with K.E is called wind energy

8. Non-Conventional sources of energy
SOLAR ENERGY
• The sun continues radiate for
5 billion yrs. more
• We are receiving S.E >5000TkWH
per sq m at the rate of
4-7kWH sq m.
• The amount of solar energy
received per sq.m per sec. on
the surface of the earth is
called Solar constant.
1.4 kj/sq m.sec
•Energy sources which do not deplete and scarcely used by the populations are
called non-conventional sources.

9. Solar Cooker

10. SOLAR PANEL
• convert S.E into current
• Silicon and Silver are used
• a cell develops a voltage
of 0.5-1V ,0.7W of current
• non-movable, little main-
tenance, can be set up in
remote
•- high cost & low efficiency
o

11. Energy from the Sea
 Tidal energy
 Wave energy
 Ocean Thermal
energy

12. Due to geological changes , molten rocks formed in
the hot regions of earth’s crust are pushed upward
and trapped in certain regions called hot spots .
hot water from hot spot region finds outlets at the
surface is known as hot springs.
The steam is routed through a pipe to a turbine
for generating electricity
Geothermal plants are in NZ and US

13. NUCLEAR ENERGY
NUCLEAR FISSION Chain reaction
The process of splitting of heavy nucleus into lighter nuclei is called fission.
E = mc 2…10M times to 1 carbon atom… ATOM BOMB

14. NUCLEAR FUSION
The process of fusion of lighter nuclei into heavier nucleus is called nuclear fusion.
The SUN ..10000000 K req…HYDROGEN BOMB…Devasting energy releases
ELWIN OLIPHANT

15. ENVIROMENTAL CONSEQUENCES
Don’ts
•Vast combustion of fossils
•Releasing of greenhouse
gases
• deforestation
• ecological imbalance
• Increasing radioactivity
Dos
 CNG
 SOLAR CELLS
 HYDROGEN FUEL
 MANAGING BIO-MASS
 RENEWABLE ENERGY
 Use of CFLs, pressure
cookers and cycles for
short distances

16. IDEA
“ If we start living as our ancestors, this would conserve
energy and our ecosystem.”
VOTE
Y E S N O
preparedby…V i v e k a n a n d T
M . S c . , B . E d . , P . G . D . C . A
Energy save is energy produce