CHAPTER 5: ELECTRICITY
5.1-Sources of Electricity
1. Electricity is the flow of electrical power or electric charges
2. The electricity we use in our homes comes from primary sources like oil,
nuclear power, coal, gas, the Sun or other natural sources.
3. Electricity is generated in power stations. Fuels like oil, coal or natural gas
are burnt in power stations to generate electricity.
4. Some power stations use fast moving water from rivers and waterfalls to
generate electricity.
5. We use electricity everyday for heat, light and power.
6. Other sources of electricity are dry cells or batteries, dynamos,
accumulators, solar cells and hydroelectric power.
BATTERIES/ DRY CELLS
DYNAMO
SOLAR CELLS
Dry cell/Battery
1. Dry cells are used to supply a small amount of electrical
energy.
2. Dry cells contain chemical substances that can be changed into
electrical energy.
3. Dry cells are used in small electrical appliances such as alarm
clocks, torches, radios and toys.
DRY CELLS/ BATTRIES
RECHARGEABLE BATTERY
1. Rechargeable batteries are batteries that can be restored to
full charge by the application of electrical energy.
2. This type of battery can be used for longer periods of time and
is used in appliances such as cameras, mobile phones and
laptops.
RECARGEBLE BATTRIES
DYNAMO
1.
2.
3.
Dynamos are fixed to bicycle wheels to light up bicycle lamps.
When the dynamo is rotated, it produces an electric current to
light up the lamp.
Dynamos convert mechanical energy to electrical energy.
DYNAMO
ACCUMULATOR
1. Accumulators are rechargeable batteries. They supply bigger
electrical energy compared to dry cells.
2. Accumulators are used in motor vehicles such cars,
motorcycles and lorries.
ACCUMULATOR
SOLAR CELLS
1. Solar cells convert light to electrical energy.
2. Generally they produce Small amount of currents.
3. Solar cells are used calculators, water heaters and satellites.
SOLAR CELL
HYDROELECRTIC POWER
1. Hydroelectric power stations use the kinetic energy of water
which is released from a dam or waterfall to turn the water
turbine and generator to generate electricity.
2. Hydroelectric power stations supply great amounts of
electrical energy to houses, offices and factories.
WATER BEING RELEASED
FROM DAM
HYDROELECTRIC POWER
STATION
ELECTRICAL APPLIANCES
I PAD
ELECTRONIC CALCULATOR
GPS
IPOD
EBOOK
IPHONE 5
NINTENDO WII
ELECTRONIC
PICTURE FRAME