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ENGINEERING FACULTY ELECTRICAL DEPERTMENT ( iii )

NUR CAHYONO

101020100004

A project submitted in partial fulfillment of two requirements for English

for specific II

ENGINEERING FACULTY ELECTRICAL DEPERTMENT

MUHAMMADIYAH UNIVERSITY OF SIDOARJO


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ACKNOWLEDGEMENTS

For this great occasion, I would like to express my gratitude to Allah S.W.T who

always gives me blessing and health so that finally I can finish this project. Inaddition, I want to thank to our prophet Muhammad SAW who guides to the

right path.

I would like to thank to some following people. At first, I want to say my

gratitude to my parent (Mother & Dad) who always give me love and support

during my life. Secondly, I also want to express my gratitude to my sister

(Novita l) who gives me support to finish this study.

My gratitude also goes to my lecturer & Teacher (Miss Rodiah & Sir Eko ) for

teaching and guiding me make this paper. And than, I want to say thank you so

much to Muhamadiah University of Sidoarjo for giving me this great chance to

study here

My great gratitude also for all my best friends. Thank you for being so nice and

helpful so that I can finish this project.


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TABLE OF CONTENTS

Acknowledgements.............................................................................................ii

Table Of Contents...............................................................................................iiiAbstract...............................................................................................................iv

CHAPTER1 INTRODUCTION

BACKGROUND OF STUDY............................................................................1

AIMOF THE STUDY.........................................................................................2

RESEARCH QUESTION..................................................................................2

RESEARCH ANSWERED................................................................................2

CHAPTER 2 LITERATUR REVIW

INTRODUCTION............................................................................................17

KNOWLADGE.................................................................................................17

CHAPTER 3

CONCLUSION................................................................................................19

DISCUSSION..................................................................................................19

REFERENCES.....................................................................21


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ABSTRACT

This study discusses some people with electrical expect about electricity?.....

Electrical charge is fundamental component of everyday matter object aremade of molecules and atoms, and now what is electrical energy, electrical

energy is a combination of two things: magnetic fields and fields. Electrical

energy can be guided by wires but also it can travel though space without any

wires. Electrons and protons are not particles of energy electrons and protons

can store energy.

Electrons are a natural part of everyday matter. Matter is full of electrons that

is important because whenever an electric current appears in a copper wire the

electrons already present with in the copper are forced to flow. Whenever

electric charge moves or flows that is an electric current, than voltage or electric

potential is one way that we can measure an electric field. Electric power

means flow rate of electrical energy if electrical energy was like water , than

electrical power would be the gallons per second. The flow is measured in

joules persecond. Electro magnetism has a wide variety of behaviors its

behavior depends on the strengths of electric field and magnetic field involved.

Electro dynamics is a field of science and a class of phenomena which involves

electric current magnetic fields and attractive/repulsive magnetic forces.

Electrostatics is a field of science and a class of phenomena which involves

charged subatomic particles, net electrical charge, electric voltage, electric field

and attractive/repulsive electric forces. So electrical science is the study of

electrical effects


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CHAPTER 1 INTRODUCTION

BACKGROUND OF THE STUDY

What is electricity? This question is impossible to answer because the word

"Electricity" has several contradictory meanings. These different meanings are

incompatible, and the contradictions confuse everyone. If you don't understand

electricity, you're not alone. Even teachers, engineers, and scientists have a hard

time grasping the concept.

Obviously "electricity" cannot be several different things at the same time.

Unfortunately we have defined the word Electricityin a crazy way. Because the

word "electricity" lacks one distinct meaning, we can never pin down the nature

of electricity. In the end we are forced to declare that there's no such stuff as

"electricity" at all! Here's a quick example to illustrate the problem.

Do generators make electricity? To answer this question, consider the

household light bulb. Inside a lamp cord the charges (the electrons) sit in one

place and wiggle back and forth. That's AC or alternating current. At the same

time, the waves of electromagnetic field move rapidly forward. This wave-

energy does not wiggle, instead it races along the wires as it flows from the

distant generators and into the light bulb. OK, now ask yourself this: when

"electricity" is flowing, is it called an Electric Current? Yes? If so, then electricity

is charge. And therefore we mustsay that the "electricity" sits inside the wires

and vibrates back and forth. Generators do not create it, and it does not flow

forward


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AIM OF THE STUDY

- AIM of study is to understand the research about Electricity

-Evolving what we research

RESEARCH QUESTION

y What is electric charge?

y What is electrical energy?

y What are electrons?

y What is electric current?

y What is voltage?

y What is electric power?

y What is electromagnetism?

y What is electrical science?

y What is electrodynamics?

y What is electrostatics?

y What are electrical phenomena?

RESEARCH ANSWERED

1. What is electric charge?

Electric charge, also called "the Quantity of Electricity," is a fundamental

component of everyday matter. Objects are made of molecules and atoms, atoms

are made of protons, neutrons, and electrons, and the protons and electrons aremade in part out of electric charge. Electric charge is substance-like. If you have a

quantity of charge, you cannot destroy it, you can only move it from place to place.

A flow of electric charge is called "electric current."


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Here's an interesting problem. Electric charge once had a different name. It was

called "electricity" by nearly all scientists throughout history. They said things like

"charge of negative electricity" or "charge of positive electricity." They calledelectric currents by the name "flows of electricity." Eventually they changed the

name and stopped using the word "electricity." They called it "electric charge" or

simply "charge." Yet the old Quantity of Electricity definition is still used by

Britannica, and the CRC Handbook, and the SI units definitions of NIST.

2. What is electrical energy?

Each of these is a kind of electrical energy:

1.X-rays

2. Light

3. Microwaves

4. Radio signals

5. Telephone signals

These five things really are exactly the same, only their frequency is different.

We can add two more items to the list above. Power lines carry the same "stuff"

as above, but the frequency is even lower, it is 60 cycles per second (50Hz in

Europe.) And batteries produce the same "stuff", but the frequency in that case

is near zero. Lets add them to the list:

y X-rays

y Light

y

Microwavesy Radio signals

y Telephone signals

y 60Hz energy from Electric company generators

y DC energy from batteries


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Electrical energy is also called "electromagnetic energy" or "EM energy" or

"electromagnetic vibrations." Electrical energy is a type of wave energy, and

these energy-waves always move very quickly (they usually move at the speed

of light.) When you turn on a wall switch, the light bulbs light up instantly

because the electrical energy moves so fast.

Electrical energy is a combination of two things: magnetic fields and

electrostatic fields. Electrical energy can be guided by wires, but also it can

travel through space without any wires. For example, if we wave a bar magnet

near a coil of wire, electrical energy produced by the moving magnet will leap

into the coil even though the magnet did not touch the coil. Another example: if

we build an antenna that's about 5000 miles long, we can plug it into an AC wall

outlet, and the electrical energy will be broadcast into space and lost. There is

no basic difference between "radio signals" and "AC Power", only their

frequency is different.

WHAT IS ELECTRICAL ENERGY? WHAT DOES IT HAVE TO DO WITH

VOLTAGE AND CURRENT?

Ooooo, good question! It ties in with " what is charge" and "what is electricity"

Here's the very briefest answer: Electrical energy (also called electromagnetic

energy) is the stuff sold by electric companies. It is produced by electric

generators, and it gets used up by lights and appliances. Electric energy is not

made of electrons or other charges. Instead it is made of electric fields, and

also is made of magnetic fields. (That's why it's also called "Electromagnetic

Energy.") If you have a bar magnet, the invisible "stuff" that surrounds the

magnet is the electrical energy. If you have a charged, fur-rubbed balloon, the

invisible "stuff" that surrounds the balloon is the electrical energy. And if you

have an electric


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circuit, the electrical energy can be found in the invisible fields that surround the

wires. Electrical energy has two faces: magnetism and "electrics" (magnetic

fields and electrostatic fields.)

Where do voltage and current come in? Easy: the voltage is part of electric

fields, and the current is part of magnetic fields. For example, whenever the

charges in a coil of wire are forced to flow along, a magnetic field appears

around the coil, and energy is stored in the magnetic field. Even if the wire is

straight and is not wound into a coil, there is still a magnetic field surrounding

the electric current in the wire. We could almost say that electric current IS the

energy, since whenever a current exists, there MUST be a magnetic field and

there MUST be energy present in that field. (We could almost say that, but not

quite, since all the energy is sitting in the fields, and it's not moving along with

the flowing charges inside the wires.)

In a similar way, voltage is profoundly connected with electric fields. Whenever

we "charge" up a capacitor, energy is stored in the electrostatic field between

the capacitor plates. The wires of an electric circuit can also act like capacitor

plates, and energy will be stored in the voltage-fields that surround the circuit. If

we have voltage, then we MUST have an e-field, so we MUST have some

electrical energy present.

Whenever a battery powers a light bulb, where is the energy flowing? Does it

flow inside the wires where the current is located? Nope. It flows in the space

outside the wires. Here's a way to think about it:

Electrons and protons are not particles of energy (they are matter.)

Electrons and protons can STORE energy. Pull an electron away from a proton

and you store energy in the space between them. Let the electron fall back

towards the proton again, and you get the energy back.


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As the electron is pulled far from the proton, does the electron change? Nope. If

not, then where is the energy being stored? It's stored in the fields! When you

pull

the electron away from the proton, the electrostatic fields around them do

change: they get much bigger. When we pull an electron far away from a

proton, the fields between them will expand like an inflating balloon. Whenever

we use electrons and protons to store energy, the energy is actually stored in

the fields in the space around them.

When we put electrical energy into an electric circuit, do the electrons and

protons of the wires become "energized?" Do they change somehow? No, only

the fields surrounding them change. The fields extend outside the wires. The

sored electrical energy is out there, outside the wires.

Whenever the electric company sends energy to our homes, does the energy

flow inside the wires? Is the voltage and current and part of the energy? Nope.

The current and the voltage are CONNECTED to the flowing energy, but all the

energy flows outside of the wires where the electromagnetic fields are. It goeslike this: CURRENT/INDUCTOR/M-FIELD, and VOLTAGE/CAPACITOR/E-

FIELD. Because even the simplest electric circuit is like a coil and a capacitor,

we have no choice but to say that the energy is stored in the fields surrounding

the wires, and is not stored inside the wires.

Get an AC generator. Connect it to a long cable, and put a light bulb on the end

of the cable. Crank the generator. It creates voltage and current which lights upthe light bulb. At the same time, the generator emits electromagnetic fields

which run along the cable and dive into the light bulb. Since the generator is

AC, these fields which run along the wires are the same as electromagnetic


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waves. The light bulb absorbs the energy of the waves, and this lights up the

bulb.

Get a radio transmitter. Connect it to a long cable, and put a light bulb on the

end of the cable. Turn on the transmitter, and electromagnetic waves flow along

the

cable and dive into the light bulb. It lights up. Another way to say it: the radio

transmitter behaves as an AC power supply which supplies voltage and current

to light the bulb. Even though we're using a radio transmitter, the voltage and

current in the cable is just the same as any other voltage and current. There's

no real difference between the radio transmitter and any other AC generator

Take the same radio transmitter, connect it to a long cable, and put an antenna

on the end of the cable. Now the radio waves come out of the transmitter, flow

along the cable, and spew right out into space! The antenna lets the

electromagnetic field-energy escape from the cable and fly outwards as radio

waves. The electromagnetic energy is flying outwards, but no voltage or current

is needed.

And finally, take the generator, connect it to a cable, then connect it to a large

antenna. What will happen when we crank the generator? The generator

creates voltage and current in the cable and in the antenna. The generator

ALSO emits electromagnetic waves which move along the cable, then they hit

the antenna and FLY RIGHT OUT INTO SPACE. Weeeeird. The electrical

energy from the generator has escaped from the wires. (But if you know thatelectrical energy *IS* electromagnetic fields, then it's not so weird that the

energy is the same as radio waves.)

Can generators really make radio waves? Yep. However, in order to get the

waves out into space, the antenna needs to be about the same size as the


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waves. At sixty cycles per second, you'd need an antenna that was many

hundreds of miles long. At the turn of the century, radio pioneers actually used

AC generators to create radio waves. They called these "alternators", and they

ran at extremely high frequencies. Since electrical energy is electromagnetic

fields, and since electromagnetic fields are the same "stuff" as radio waves, it

makes sense that the energy in electric circuits can also fly through empty

space all by itself.

3. What are electrons?

Everyday matter is composed of atoms, right? But atoms are composed of

protons, neutrons, and electrons. This tells us that atoms are patterns, and that

that everyday matter is just a big bunch of protons, neutrons, and electrons.

Electrons are a natural part of everyday matter. MATTER IS FULL OF

ELECTRONS. This is important, because whenever an electric current appears in

a copper wire, the electrons already present within the copper are forced to flow.

As far as wires are concerned, "electric current" means "copper's electrons start

flowing."

Here's the most important part: batteries and generators don't put those electrons

into the wires. The electrons were already there, because wires are made partly of

electrons. When you plug a lamp into an AC outlet, the electrons already inside the

copper wires are forced to vibrate back and forth.

An analogy: if sound is like electrical energy, then air molecules are like electrons.

How do sound waves travel? They are travelling vibrations in the air. How does

electrical energy travel? It is a vibration that travels in the "cloud of electrons"inside of metals.

4. What is electric current?

Whenever electric charge moves or flows, that is an electric current. The words

"electric current" are the same as the words "charge flow."


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An Analogy: If charge is like air, then electric current is like wind. Or if charge is

like water, then Electric Current is like "gallons per second" of water flow.

5. What is voltage?

"Voltage" or "electric potential" is one way that we can measure an electric field. To

produce a very high voltage, rub a balloon on your head, or scuff your shoes upon

the floor when the humidity is very low.

Electric fields can push or pull upon electric charges, so electric forces are caused

by voltage (or instead we could say that voltage and electric forces are caused by

electric fields.) In a battery circuit, the voltage from the battery causes the charges

of the wire to flow. VOLTAGE CAUSES CURRENT. Some people like to say that

voltage is a sort of "electric pressure." That's almost correct (it's correct as far as

grade school is concerned, but in physics classes we will learn that voltage is not

pressure, not exactly.)

6. What is electric power?

"Electric power" means "flow rate of electrical energy." If electrical energy was like

water, then electric power would be the gallons-per-second. Energy is measured in

Joules, and when energy flows, the flow is measured in Joules per second. What

is a watt? The word "Watt" is just another way of saying "Joule per Second."

Energy comes in Joules, while power comes in Joules per second.

The important part: while energy is very much like a stuff, power is not. Power is a FLOW

RATE of energy, or a RATE OF USE of energy. We can store electrical energy, but electric

power is not something that is ever stored. (Think in this way: we can store gallons of water,

but it's impossible to store any "gallons per second" of water.)?

7. What is electromagnetism?

"Electromagnetism" usually means "electrical energy" or "electromagnetic fields."

Example: "Static" Electricity versus "Current" Electricity


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Are "static" and "current" really two separate kinds of electricity? I say no. There is only

one type of electrical energy. We usually call it Electromagnetism. It's true that

electromagnetism has a wide variety of behaviors. Its behavior depends on the

strengths of the electric field and magnetic field involved. Electric field corresponds to

voltage, and magnetic field corresponds to current. The "map" below is intended to

show us that "static electricity" and "current electricity" are really just two fields of

science. But electromagnetism itself is a seamless whole, and the boundaries

between its various parts exist only in our minds.

Electromagnetism. Also called "E and M." In EM, its electric field corresponds to

voltage, and its magnetic field corresponds to current. Therefore it's possible to place

"static electricity" and "current electricity" upon different regions of a single map. Themap is plotted in terms of e-field (voltage) on one axis and magnetism (current) on

the other. Does this tell us that there really is no such thing as "static electricity" or

"current electricity"? Yes! Only electrical devices and electrical phenomena exist, and

these devices and phenomena can have various ratings of voltage and current.


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"Electromagnetism" has different regions.

In view of the "electricity map", here is how we usually divide up Electricity:

Electrical happenings which involve HIGH VOLTAGE at low current. CURRENT

ELECTRICITY

Electrical happenings which involve HIGH CURRENT at low voltage.

Refer to the above map, and note that the left-hand side contains the things involving

"current", while the right-hand side has the "static." Things aren't perfect, e.g. where

do we put the lightning and the high voltage power lines? These are both

electrostatic phenomena and electrodynamics phenomena at the same time.

I believe that talk of "two kinds of electricity" called Current and Static is profoundly

misleading. It hides the true nature of electric charge. It's like saying that there are

two kinds of water, pressurized water and flowing water. Yet water is water, and

water doesn't magically turn into a special kind of substance called "Current Water"

whenever it starts flowing! There is no such thing as "current water," and there is no

such thing as "current electricity." If something is flowing inside of wires... just say it

that way. Don't pretend that a form of energy called "current electricity" exists.

If fur rubbed upon rubber causes a high voltage at nearly zero current, why not

simply say so, instead of discussing a nonexisent "kind" of electricity called "Static?"

In truth, "static" is a separation of negatives from positives, and if the separated

charges should move along, that is (ahem!) ...A *FLOW* OF STATIC ELECTRICITY.

'Static' means unmoving, so what the heck is a static flow? Something is seriously

wrong with how we explain electricity. The cure is simple. Cross out the words "static

electricity" everywhere. This forces us to seek out better words to replace it.

8. What is electrical science?

Electrical science is the study of electrical effects... and electrical effects are

caused by electric charges and by the electric and magnetic fields associated with


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charges. Electrical science is divided into sections called Electrodynamics,

Electrostatics, Magnetism, and EM wave mechanics.

Electrical science is often called "electricity," which can be confusing. For example,

the study of lightning is the study of electrical science, so the study of lightning is

the

study of "electricity." But this doesn't mean that lightning is "made" of electricity.

When we study lightning, we are studying a science topic, and we're not studying a

substance called "electricity."

It might be better if electrical science had some other name than "electricity." After

all, the study of light is not called light. It's called optics. Nobody thinks that lenses

and light bulbs are made out of light, since whenever we study lenses and light

bulbs, we study "optics." Optics is obviously a science topic. But plenty of people

think that lightning is made out of electricity, since whenever we study lightning, we

study a science topic named Electricity, and most people imagine that we're

studying a SUBSTANCE named "electricity." which looks like blue-white fire that

reaches across the sky.

"Electricity" or Electrical Science is confusing in another way. This science topic is

divided into two sections called Electrostatics (the study of charge and voltage),

and Electrodynamics (the study of current and changing fields.) Many people have

convinced themselves that there are two kinds of electrical energy: static and

current. Wrong. In truth, there are two kinds of ELECTRICAL SCIENCE:

Electrostatics and electrodynamics Since "electrical science" is called "electricity,"

we can say that the two types of electricity are static and current. What we MEAN

is that the two types of electrical science are the study of charge and the study of

charge-flow. See what's happening here? A field of science has been mistaken for

a type of energy! And the two fields of science, Statics and Dynamics, have been

mistaken for two separate KINDS of energy.

How many K-6 textbooks insist that "static electricity" and "current electricity" are

the two main forms of energy? This is a weird distortion which probably arose over

many years of misunderstanding. What they MEAN is that there are two types of


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electrical science, one dealing with charge and voltage, and the other dealing with

currents and circuits. Two kinds of "electricity," where the word "electricity" means

Electrical Science.

9. What is electrodynamics?

Electrodynamics is a field of science and a class of phenomena which involves

electric current, magnetic fields, and attractive/repulsive magnetic forces. The

study of generators, motors, circuitry, electric currents, etc., falls under the heading

of "electrodynamics."

10.What is electrostatics?

Electrostatics is a field of science and a class of phenomena which involves

charged subatomic particles, net electrical charge, electric voltage, electric fields,

and attractive/repulsive electric forces.

11.What are electrical phenomena?

"Electrical phenomenon" means "electrical happening." When you turn on aflashlight, that is an electrical phenomenon. During a thunderstorm, the thunder is

an electrical phenomenon and the flashes of light are electrical phenomena.

Unfortunately the term "electricity" means "electrical phenomenon." This causes

confusion, because sparks, wires, batteries, currents, and voltage are all electrical

phenomena, so they are forms of electricity. See what I just said? Batteries ARE

ELECTRICITY. Sparks ARE ELECTRICITY. Electron flows ARE ELECTRICITY.

But these are not such odd statements. After all, transistors and radios and

computers are electronics. When we hear about "electronics", we don't end up

thinking that "electronics" is some kind of weird invisible energy that's hidden

inside our computer. The word "electronics" fortunately has a clear meaning.


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Not so with "electrical phenomena" or "electricity." If someone tells you that motors

are electricity, you'll probably get the right idea (motors are electricity just as

transistors are electronics.) But if someone tells you that lightning is electricity, or

that electric currents are electricity, you probably WON'T decide that lightning and

currents fall under the heading of electrical phenomena. Instead, you'll probably

decide that currents and lighting are MADE OUT OF "electricity," and that

"electricity" is a very strange substance indeed.


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CHAPTER 2LITERATURE REVIEW

INTRODUCTION

This is chapter, it will be discussed. Know. All people has familiar withtechnology, so not fault if we know about electricity knowledge.

This is project is going to research in accordance with complete about

electricity.

If we wish to agree on a single correct definition of "electricity," which definition

should we choose? Well, maybe we don't need to choose just one. Suppose we

ignore all these contradictions and instead pretend that ALL of the abovedefinitions are true. Below is the "clear" and "simple" description of electricity

that results:

KNOWLADGE

Electricity is a mysterious incomprehensible entity which is invisible AND visible

BOTH AT THE SAME TIME. Also, it's both matter and energy. It's a type of low-

frequency radio wave which is made of protons. It is a mysterious force whichlooks like blue-white fire, and yet cannot be seen. It moves forward at the speed

of light... yet it vibrates in the AC cord without flowing forwards at all. It's totally

weightless, yet it has a small weight. When electricity flows through a light

bulb's filament, it gets changed entirely into light. Yet no electricity is ever used

up by the light bulb, and every bit of it flows out of the filament and back down

the other wire. College textbooks are full of electricity, yet they have no electric

charge! Electricity is a class of phenomena which can be stored in batteries! If

you want to measure a quantity of electricity, what units should you use? Why

Volts of electricity, of course. And also Coulombs of electricity, Amperes, Watts,

and Joules, all at the same time. Yet "electricity" is a class of phenomena; it's a


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type of event. Since we can't have an AMOUNT of an event, we can't really

measure the quantity of electricity at all... right?.

Does my description above sound stupid and impossible? You're right. It is. The

word "electricity" has contradictory meanings, and I'm trying to show what

happens when we accept more than one meaning. Electricity is notboth slow

and fast at the same time. It is notboth visible andinvisible.

Instead, approximately ten separate things have the name "electricity." There is

no single stuff called "electricity." ELECTRICITY DOES NOT EXIST. Franklin,

Edison, Thompson, and millions of science teachers should've had a long talk

with Mrs. Mc Cave before they decided to give a variety of independent science

concepts just one single name.


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CHAPTER 3

CONCLUSION

Electricity is a kind of energy, it can be used in many ways for example :

Microwaves, Radio Signals, X- rays and the others. Electrical energy is also

called electromagnetic energy or En energy or electromagnetic vibrations

these energy waves always move very quickly.

Electrical energy is a combinations of two things: magnetic fields and

electrostatic fields. Electrical energy can be produced by electric company and

they sand the current and the voltage are connected to the flowing energy byusing a low cable.

Electricity is also a general term encompassing a variety of phenomena

resulting from the presence and flow electric charge. These include many easily

recognizable phenomena, such as lighting, static electricity and the flow of

electrical current and electrical wire, in addition, electricity encompasses less

familiar concepts such as the electromagnetic field and electromagnetic

induction.

DISCUSSION

Each of these is a kind of electrical energy:

6. X-rays

7. Light

8. Microwaves

9. Radio signals

10.Telephone signals


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These five things really are exactly the same, only their frequency is different.

We can add two more items to the list above. Power lines carry the same "stuff"

as above, but the frequency is even lower, it is 60 cycles per second (50Hz in

Europe.) And batteries produce the same "stuff", but the frequency in that case

is near zero. Lets add them to the list:

y X-rays

y Light

y Microwaves

y Radio signals

y Telephone signals

y 60Hz energy from Electric company generators

y DC energy from batteries

Electric charge is a component of atoms. In other words, after we have broken

an object into molecules, and broken the molecules into atoms, when we break

the atoms apart we discover particles of electric charge.

If the positive and negative charges move along together, we call it "physical

motion." Since matter is composed of charge-carrying particles, all physical

motion is a motion of charge, but in most cases both the negative and the

positive charges move along as one.

When the positive and negative charges of matter are sorted out and pulled

away from each other, "static electricity" is the result. When (+) is pulled away

from (-), an invisible force field connects them and causes them to attract each

other.


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REFERENCES

William J. Beaty Electrical Engineer

From Wikipedia, the free encyclopedia

http://www.brainpop.com/science/electricity/electricity/index.wemlhttp://library.thinkquest.org/16600/intermediate/electricity.shtml

http://tqjunior.thinkquest.org/6075/http://library.thinkquest.org/J0112709/http://library.thinkquest.org/J001647F/

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