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Conductors and Insulators: Electrical Properties of substance
All the substances shows specific characteristic with electricity. Some
substances allows the electricity to pass through it and some not allows to
pass through it; Both the properties of the substances are very useful in
electricity. On the basis of these properties all the substances has been
categorized in to groups. In this unit we will learn about the substances
and their property towards electricity.
All substance available around us are made of tiny part
called molecules. These molecules are made of smaller
tiny parts called atoms. To understand concept of
conductor, insulator or electricity it is very necessary to
understand the “Atom”.
Atom
Before we can understand conductor, insulator or electricity we have to
know some things about atoms.
Each Atom is comprised of three main particles
Protons, which are positively-charged;
Electrons,
which
are
negativelycharged, and
● Neutrons, which have no charge.
●
●
At the core of all atoms is the nucleus. The
nucleus contains one or more protons and may
also contain neutrons.
Orbiting around the nucleus is one or more electrons. Electrons have a
negative charge and are very small compared to protons and neutrons.
The nucleus is very heavy compared to its electrons.
The hydrogen atom is the simplest of all atoms. The
hydrogen atom has one proton and one electron. A
hydrogen proton has a mass of approximately 1850
times the mass its an electron.
Elements are classified by the number of protons they
have. This is the atomic number. This is what differentiates the basic
elements.
For example,
●
●
●
●
If an atom has one proton then its a hydrogen atom,
If an atom has two protons then its a helium atom and
An atom with three protons would be lithium.
Copper has twenty nine protons.
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Conductors and Insulators: Electrical Properties of substance
Normally an atom has the same number of electrons as it has protons.
When the number of electrons equals the number of protons the atom's
total electrical charge is balanced or neutralized.
Ion
If the atom loses an electron it has more protons than electrons and
therefore it’s total charge is positive.
If the atom gains an extra electron it contains more electrons than
protons and has an overall negative electrical charge.
When an atom has an imbalance of electrons and protons it is said to be
ionized.
●
●
An atom with a positive charge is a called a positive ion.
An atom with a negative charge is called negative ion.
A positive ion will exhibit an electron attraction while a negative ion will
try to lose its extra electron.
Protons and Electrons follow specific Laws of Attraction. Since they have
opposite charges, they "attract" to one another. If an Atom has the same
number of Protons as Electrons, then the Atom is balanced and stable.
The orbiting Electrons remain in their "orbits" as long as nothing upsets
the balance.
When something upsets this balance, then some of the Electrons become
"knocked out" of their "orbits". They are called "Free" Electrons. This
unbalanced condition can be caused by rubbing cat's fur on Amber,
passing a Wire through a Magnetic Field, or putting two chemicals
together (as in a Dry Cell Battery).
Conductors
Materials which are made up of Atoms whose Electrons are easily frees to
move are called "conductive materials" or "Conductors." When an electric
Voltage is applied across separate points on the material electrons starts
moving.
Platinum, Gold, and Silver are examples of the very best Conductors of
electricity. Gold is used extensively in small quantities for high-value
products like: microelectronics, high quality audio components, computer
chips, and telecommunications satellites.
Copper and Aluminum are also very excellent Conductors of electricity
and much less expensive. Almost all Electrical Wiring is Aluminum or
Copper, although many actually contain some for added strength.
Copper Wires
Copper Wire is commonly used on the "customer side" of the Electric
Meter. While Copper generally costs more than Aluminum, it is a better
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Conductors and Insulators: Electrical Properties of substance
Conductor, so smaller Wire can be
used. Copper also requires less
maintenance.
Aluminum Wires
Aluminum Wire is used as Electrical Conductors on electric utility
transmission and distribution systems. The Overhead Wires spanning
Utility Poles are made of Aluminum and do not have Insulation around
them.
Aluminum has two advantages over Copper as a Conductor for Utility
Lines:
It is lightweight and economical. The
light weight permits larger "spans"
between Poles.
● Because Aluminum costs less than
Copper, it helps Utilities keep costs
down.
●
Most Electrical Codes do not permit
Aluminum Wiring in residential buildings.
Aluminum can be used in many commercial
and industrial buildings provided it is
installed and maintained under strict rules.
Insulators
A material in which atoms not easily frees electrons from its orbit to move
freely even on applying external force, such as applying electric Voltage.
Such materials are called “Insulators".
Insulators are materials that have structural properties exactly opposite of
Conductors. The electrons of Insulator material atoms are not easily
"freed." These Electrons are said to be tightly bound to the "nucleus" and
are very stable. Due to this high stability of electrons of atoms of
Insulator no current flows in the insulating materials.
In Electricity the Insulators are used to prevent the flow of electrical
current. The rubberized Power Cord and plastic coverings on Appliances
are typical examples of Insulators. Glass, rubber, porcelain, and most
plastics are good Insulators.
In electricity the Conductor and insulators are complementary of each
other; the role of insulators is equally important in term of Safety and the
conductors provides path for flow of electric current.
Q1. Pick Conductors and Insulators
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Conductors and Insulators: Electrical Properties of substance
Safety Pin, Plastic Scale, Wooden Scale, Steel Spoon, Thread, Bamboo
stick, Iron Bucket, Plastic Bucket, Steel Glass, Mirror, Rubber Ball, Cricket
Bat, Iron Box, Gold Chain, Silver Chain, Iron Chain, Normal Pen, Pencil,
Rubber (eraser), Water, Cold Drink.
Q2. Write about three main Parts of Atom.
Q3. What do you mean by conductive materials or conductors?
Q4. What do you mean by Non Conductive materials or Insulators?
Make a list of conductive items available at your home.
Draw a conductor test diagram
Connect cells bulb and wire in open condition connecting with a
conductor (Iron Box) Q. bulb will glow or not?
2. As above only replace iron box with pencil.
3. Same circuit any device is connected but bulb is not glowing which
type of material is this.
4. Same circuit any device is connected but bulb is glowing which type
of material is this.
1.
You can try websites:
http://www.andythelwell.com/blobz/guide.html
http://iq-technologies.net/downloads/index.htm
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Conductors and Insulators: Electrical Properties of substance
Conductor
Conductor is the word used to describe
any material or substance that allows
electricity to travel through it.
Almost all conductors are metals,
butgraphite, which is what pencil 'lead' is
made from, also conducts electricity.
Insulator
An insulator is a material or
substance that does not allow
electricity to travel through it.
Plastic, rubber, glass and wood are all
examples of insulators.
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