“WELCOME”

“ELECTROSTATIC

CHARGING”

What is ELECTROSTATIC CHARGING?

ELECTROSTATIC-a term used to emphasize that

relative to each other, the charges are either stationary or

moving very slowly.

- before learning what charging means, you need to be able to distinguish between substances and their ability to conduct or transmit electric charge.-

;)

“CONDUCTORS”

ARE MATERIALS THAT PERMIT ELECTRIC CHARGE

TO MOVE FROM ONE REGION TO ANOTHER!

WHILE..,,

“INSULATORS”ARE MATERIALS THAT DO NOT

PERMIT THE PASSAGE OF CHARGE THROUGH THEM.

The properties of conductors and insulators are due to the structure and electrical nature of atoms.

A general picture is that in conductors, valence electrons of atoms are loosely bound. As a result, valence electrons can be easily removed from the atoms and moved about in the conductor. In insulators, the valence electrons are more tight and are not readily moving

There is no sharp boundary between materials which are insulators and those which are conductors.

All materials can conduct electricity to some extent.

SEMICONDUCTORS

are intermediate class of materials,.

have the ability to conduct charge less than that of metals(conductors) but much greater than that of nonmetals(insulators)

The conductivity of semiconductors can be adjusted by adding certain

types of atomic impurities in varying concentrations.

The microelectronic revolution that has transformed our lives in so many ways due to devices constructed of

semiconducting materials.

Relative Magnitude of Conductivity

MATERIALS

108

107

CONDUCTORSSILVER

COPPER

ALUMINUM

IRON

MERCURY

CARBON

107

10-9

SEMICONDUCTORS

GERMANIUM

SILICON

10-10

10-12

10-15

INSULATORS

WOOD

GLASS

RUBBER

IN THE TABLE..Some of the common

substances are arranged roughly in the

descending order of their electrical conductivities.

The characteristics of the electric charge can

be demonstrated using an electroscope.

-a device consisting of a rod with a metallic bulb at one end and a pair of hanging foil leaves, usually made of gold or aluminum at the other end. This arrangement is insulated from its protective glass container by a rubber cork.

CHARGING- means gaining or losing electron. IN GENERAL…

“ELECTROSTATIC CHARGING”-IS A PROCESS BY WHICH AN INSULATOR OR AN INSULATED CONDUCTOR RECEIVES A NET CHARGE.

Charging can be done by:• FRICTION

• CONTACT OR CONDUCTION• INDUCTION AND;• POLARIZATION!

“FRICTION”When you rub one material to another, they are

charged by friction. Material losing electron is positively charged and material gaining electron is negatively charged. Amount of gained and lost electron is equal to each other. In other words, we can say that charges of the system are conserved. When you rub glass rod to a silk, glass lose electron and positively charged and silk gain electron and negatively charge.

“CONDUCTION”

• .The process of charging that requires contact between the neutral body and the charged object. It produces similar object.• Refers to the way of charge during

the short period of time the electrons move.

For example:A negatively charged rod is brought in

contact with neutral electroscope. Charges are transferred to the bulb and the

electroscope becomes negatively charged.When a negatively charged rod is again

brought closer to the bulb, the metal leaves separate further because the rod repels the electrons ; but when a positively charge rod is brought near the bulb, the rod attracts electrons and the leaves collapse.

By touching the bulb w/ finger, the electroscopes becomes(+) charged because the action causes grounding of the electroscopes that provides a path by w/c electrons can escape the bulb.

Thus, when a negatively charged rod is brought close to the bulb, the rod repels from the bulb into the finger and down into the earth.

When the finger is removed while the charged rod is kept closely , the electroscope is left with a positive charged because the removed electrons have no means of flowing back once the ground path is removed.

“INDUCTION”

A process of charging that does not require contact but does require the presence of a ground. It produce opposite charges.

“POLARIZATION” or separation of charge explains how a

balloon will stick to the wall or ceiling after it was rubbed on your hair or sweater.

In the image above, the balloon collected negative charges from the sweater. When placed near the right wall, the negative charges repel, polarizing the wall and attracting the balloon.

In variety applications, electrostatic charging is beneficial. For instance, the air we breathe is cleaner because of electrostatic precipitation-

-where an electric field exerts a force on charge ash as it ascends a smoke attack, so that much of it is collected in the stack; hence , does not enter and pollute the atmosphere.

“THE END”THANK YOU.,

HOPE YOU UNDERSTAND!

PREPARED BY:LOUIE ANN ABDON