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Current Electricity
What is Current Electricity?
Think of all the ways you use electricity each day.
You awake to an alarm clock or the radio, turn
on an electric light, use an electric toothbrush or
make toast. You watch television, listen to
music, and use air conditioners. Just think about
lights. Almost every place you go you find
electrical lighting.
**Don’t copy just think about it!
About one hundred years ago there was
no electricity in homes, schools, factories
or offices.
Try to imagine your life without electricity!
In your notebook write down 5 things that
would be very difficult to do if you didn’t
have electricity.
The electricity that works all of your
electrical appliances is called current
electricity.
A current means flow.
Current electricity comes from a flow of
electrons.
Electrons move along a
path called a circuit.
While the electrons are
moving, the circuit is
complete.
If the electrons stop
moving, the circuit is
incomplete and the
electricity stops.
http://phet.colorado.edu/en/simulation/signalcircuit
How do we generate
electricity?
In your notebooks list 5 ways
Hydro
Some power stations use water to spin
giant generators.
These are called Hydro Power Plants.
Hydro means water.
Wind Power
The power of the wind turns the blades
and rotor of the wind turbine
The rotor is attached to a shaft which
spins and this energy is captured and
converted into electricity by a generator
Nuclear Power
Provides 13% of the world’s electricity
Captures the energy from a nuclear
reaction (on a large scale) to create
electricity and heat
Very efficient heat/energy source
Clean burning energy but the waste that it
leaves behind is highly toxic
Solar Power
Solar mirrored panels gather the sunlight
The photovoltaic cells collect, condense
and convert the sun’s energy into an
electric current or uses the energy to boil
large amounts of water which is then used
to generate heat and electricty
Can be harnessed commercially (for mass
uses) or on a small scale (home owners)
Nova Scotia Electricity
Here we mostly burn coal or oil to make
steam which is then used to spin the coils
of the generators.
These types of power plants are known as
thermal power plants (Thermal)
Electrical generators are turning
mechanical energy into electrical energy
These large generators are producing
alternating current.
Making Current Electricity
Current electricity can also be made by
chemical means.
A battery is a device which makes
electricity by using chemicals.
Electricity always flows from the negative
to the positive.
Batteries use this principal to make current
electricity.
Researchers found that the simplest
electricity making unit or electric cell was
two plates of different metals in a jar filled
with liquid.
The metal plates are called electrodes.
They are conductors.
The positive electrode is called the
cathode.
The negative electrode is called the
anode.
Kinds of Batteries
There are two kinds of batteries:
– One which has liquids in it
– One which is made from dry substances
A battery in your car has liquid acid in it.
A battery in your flashlight is a dry cell
battery. It is made with dry substances.
Dry cell batteries are safer and more
convenient to use.
A battery is basically made up of chemicals
When connected to a circuit and a switch is
turned on, chemical reactions start to occur
The electrons start flowing out the anode,
through the circuit and back through the cathode
When the chemical reactions stop, the voltage of
the battery starts to dwindle.