Electricity is the flow of electrons from one place to another. It flows more easily through conductors than insulators. The resistance of a material determines how easily electrons flow through it and is measured in Ohms. Electricity can be direct current (DC), where the electron flow is continuous in one direction, or alternating current (AC), where the electron flow alternates direction rapidly. Voltage is the "push" that causes electron flow. Current is the intensity of electron flow, measured in Amps. Power is a measurement of the work performed and is calculated by multiplying voltage by current in Watts.

1. Basic
electricity

2. Electricity is the flow of electrons from one
place to another. Electrons can flow through
any material, but does so more easily in some
than in others. How easily it flows is called
resistance. The resistance of a material is
measured in Ohms.
Electricity

3. Matter can be broken down into:
 Conductors: electrons flow easily. Low resistance.
 Semi-conductors: electron can be made to flow under
certain circumstances. Variable resistance according to
formulation and circuit conditions.
 Insulator: electrons flow with great difficulty. High
resistance.

4. Since electrons are very small, as a practical matter they
are usually measured in very large numbers. A Coulomb is
6.24 x 1018 electrons. However, electricians are mostly
interested in electrons in motion. The flow of electrons is
called current, and is measured in AMPS. One amp is
equal to a flow of one coulomb per second through a
wire.

5. Making electrons flow through a resistance requires an
attractive force to pull them. This force, called Electro-Motive
Force or EMF, is measured in volts. A Volt is the force
required to push 1 Amp through 1 Ohm of resistance.

6. As electrons flow through a resistance, it performs a certain
amount of work. It may be in the form of heat or a magnetic
field or motion, but it does something. This work is called
Power, and is measured in Watts. One Watt is equal to the
work performed by 1 Amp pushed by 1 Volt through a
resistance.

7. NOTE:
AMPS is amount of electricity.
VOLTS is the Push, not the amount.
OHMS slows the flow.
WATTS is how much gets done.

8. There are 2 standard formulae that describe these
relationships.
Ohm's Law: Where
R = Resistance (ohms)
E or V = Electro-motive Force (volts)
I = Intensity of Current (amps)

9. Ohm's Law:

10. To express work done: Power formula (PIE Law):
Where:
P = Power (watts)
I = Intensity of Current (amps)
E = Electro-motive Force (volts)
P = IE

11. This law is often restated in the units of measure as the
West Virginia Law:
W = VA
for
Watts = Volts x Amps

12. All this is important because all electrical equipment has a
limit to how much electricity it can handle safely, and you
must keep track of load and capacities to prevent failure,
damage, or a fire.
For example, a lamp is rated at 1000 w. @ 120 v. That
means that at 120 volts it will use:
1000 w. / 120 v. = 8.33 a.

13. Types of Electricity
• AC - ALTERNATING CURRENT
• DC – DIRECT CURRENT

14. Types of Electricity
• AC - ALTERNATING CURRENT
• DC – DIRECT CURRENT

15. ALTERNATING CURRENT
Alternating current or AC
electricity is the type of
electricity commonly used in
homes and businesses
throughout the world.

16. While the flow of electrons
through a wire in direct current
(DC) electricity is continuous in
one direction, the current in AC
electricity alternates in direction.
The back-and-forth motion
occurs between 50 and 60 times
per second, depending on the
electrical system of the country.
ALTERNATING CURRENT

17. AC is created by an AC electric
generator, which determines the
frequency. What is special
about AC electricity is that the
voltage in can be readily
changed, thus making it more
suitable for long-distance
transmission than DC electricity.
ALTERNATING CURRENT

18. ALTERNATING CURRENT SOURCE

19. In a direct-current system, it's
easy to determine voltage
because it is nonvarying or
varies slowly over time. You can
simply make a measurement
with a DC voltmeter. But in an
AC circuit, the voltage is
constantly changing.
DIRECT CURRENT

20. In a direct-current system, it's
easy to determine voltage
because it is nonvarying or
varies slowly over time. You can
simply make a measurement
with a DC voltmeter. But in an
AC circuit, the voltage is
constantly changing.
DIRECT CURRENT

21. DIRECT CURRENT ALTERNATING CURRENT

23. Six ways to generate electricity
Some are more widely used than others. Some are used
just for specific applications.

24. Six ways to generate electricity
Some are more widely used than others. Some are used
just for specific applications.
FRICTION — Voltage is produced when you rub certain
materials together, like a balloon on your sweater. This was
the first kind of electricity humans recognized. A Van de Graaff
generator produces millions of volts with friction. It is not a
very practical way to generate useful voltage—right after the
big ZAP!ZAP!ZAP! the voltage disappears.

25. Six ways to generate electricity
Some are more widely used than others. Some are used
just for specific applications.
PRESSURE (piezoelectricity) — Voltage produced by
squeezing crystals of certain substances like quartz or
tourmaline. Pronounced “pee-ay’-zoe”. The microphone in a
mobile phone is sensitive to sound pressure because it is
made with a piezoelectric alloy called PZT, lead zirconate
titanate.

26. Six ways to generate electricity
Some are more widely used than others. Some are used
just for specific applications.
HEAT (thermoelectricity) — Voltage is produced by heating
the junction between two different metals that have been
welded together. This device is called a thermocouple. It is
used to sense temperature. The schematic symbol looks like
this,

27. Six ways to generate electricity
Some are more widely used than others. Some are used
just for specific applications.
LIGHT (photoelectricity) — Voltage is produced when light
hits a photosensitive (light sensitive) substance.
Semiconductor materials like silicon are light sensitive. A
photodiode is in a package with a window on top to allow light
to hit the diode. The amount of light changes the conductivity
of the diode.

28. Six ways to generate electricity
Some are more widely used than others. Some are used
just for specific applications.
CHEMICAL — Voltage can be created by a chemical
reaction. We call this a battery. Chemical action generates
voltages inside your nerve cells.

29. Six ways to generate electricity
Some are more widely used than others. Some are used
just for specific applications.
MAGNETISM — Voltage produced when the wire moves
through a magnetic field, or a magnetic field moves past a
conductor. This is how AC electricity is created in large-scale
power plants, hydroelectric dams, and portable/emergency
generators.

35. Types of power plants for
energy generation

36. 1. Nuclear power
plants

37. 1. Nuclear power plants
Using a nuclear fission reaction and
uranium as fuel, nuclear power plants
generate a high amount of electricity.
As nuclear power plants are considered to
be a low-carbon energy source, the
technology is widely thought of as a more
environmentally-friendly option.

38. 1. Nuclear power plants
When compared to renewable sources of
energy such as solar and wind, the power
generation from nuclear power plants is
also considered to be more reliable.
Although the investment required to bring
a nuclear power plant online is significant,
the costs involved in operating them are
relatively low.

39. 1. Nuclear power plants
Nuclear energy sources also have a higher
density than fossil fuels and release large
amounts of energy.
Due to this, nuclear power plants require
low quantities of fuel but produce a vast
amount of power, making them particularly
efficient once they are up and running.

40. 2. Nuclear power plants
Nuclear energy sources also have a higher
density than fossil fuels and release large
amounts of energy.
Due to this, nuclear power plants require
low quantities of fuel but produce a vast
amount of power, making them particularly
efficient once they are up and running.