ELECTRICITY
How is Electricity Generated?
When a magnetic field is in motion relative to a
copper wire, it triggers the flow of electrons in
the wire, creating electricity.
Electricity Timeline
1752
1786
1800
Benjamin Franklin invented the lightening rod - he
demonstrated lightning was electricity.
Italian physician, Luigi Galvani demonstrated what we now
understand to be the electrical basis of nerve impulses when
he made frog muscles twitch by jolting them with a spark from
an electrostatic machine.
First electric battery invented by Alessandro Volta. Volta
proved that electricity could travel over wires.
1820
Hans
Relationship of electricity and magnetism confirmed by
Christian Oersted who observed that electrical currents
effected the needle on a compass and Marie Ampere,
who discovered that a coil of wires acted like a magnet
when a current is passed thorough it.
1821
1826
First electric motor invented by Michael Faraday.
Ohms Law written by Georg Simon Ohm states that "conduction
law that relates potential, current, and circuit resistance"
1831
Principles of electromagnetism induction, generation and
transmission discovered by Michael Faraday.
1879
1886
Edison demonstrates his incandescent lamp, Menlo Park,
New Jersey.
The Westinghouse Electric Company is organized. 40 to
50 water powered electric plants reported on line or under
construction in the U.S. and Canada.
Direct current electricity flows in one direction all the
time. Electricity using batteries is DC electricity. The
poles of a battery always stay the same.
AC electricity is also known as alternating current.
The electrical source switches (alternates) polarity
many times a second. AC electricity is what comes
out of your outlets at home.
NEVER PLAY WITH POWER OUTLETS!!
The steady flow of electricity is called
an electric current. A current will
move along a wire or a path called
a circuit. Amps are used to
measure how much electric
current is moving through a wire.
Circuit means to “go around.”
•
•
•
•
Has a single loop for electrons to travel round
Components are connected one after another
Current is the same at all points
Voltage is shared between components
• Has two or more paths for electrons to flow
down
• Current is shared between the branches
• Sum of the current in each branch = total
current
• Voltage loss is the same across components
• Lights in our homes are
wired in parallel circuits.
Current measured in amps (A)
Voltage (V) – Increase or decrease in the
amount of electrical energy carried by the
current.
Parallel Circuit
Wire
Cell/Battery
Light
On/off switch
Resistor
Voltmeter
Ohmmeter
Series Circuit
KEY:
o P= Power
o E= Voltage
o I= Current
o R= Resistance
Wind Power
Hydropower
Geothermal Power
Solar Power
Biomass Energy
Wind power, hydropower, and geothermal energy work basically
the same way. A movement in the environment causes a
turbine to spin which spins a generator. The generator converts
the mechanical energy to electrical energy.
Wind turbines can be found all over the
US but the most productive states are
Texas, Iowa, California, and Washington.
• Moving water turns a turbine.
• Hydropower plants are found
in places with dams or
waterfalls.
• It accounted for 6% of total
U.S. electricity generation and
67% of generation from
renewables in 2008.
Geothermal energy can be
found where hot spots are
located in the earth.
Geothermal energy is heat from
within the Earth. We can recover
this heat as steam or hot water
and use it to heat buildings or
generate electricity.
Geothermal energy is a renewable energy source because the heat is
continuously produced inside the Earth.
Solar energy can be converted
to electricity in two ways:
Photovoltaic cells (or solar
cells) and Concentrating Solar
Power Plants
Photovoltaic cells change
sunlight directly into
electricity while concentrating
cells generate electricity by
using the heat from solar
thermal collectors to heat a
fluid which produces steam
that is used to power the
generator.
When woods,
crops, manure,
and some garbage
are burned, the
chemical energy in
biomass is
released as heat.
These things can
be burned to also
produce steam
which can
generate
electricity.
Country
Average KWH
United States
3,920,613,000,000
China
2,054,568,000,000
Japan
1,031,262,000,000
Canada
548,794,000,000
Mexico
187,617,000,000
Haiti
256,000,000
5% (USA population) of the world’s
population consumes 23% of its energy!
What is Energy Star?
ENERGY STAR is a joint program of the U.S.
Environmental Protection Agency and the U.S. Department
of Energy helping us all save money and protect the
environment through energy efficient products and
practices.
http://buckeyephysics.pbworks.com/kristina-and-lindsay-presentation