STATIC ELECTRICITY by Sukesh Kamath

sukeshkamath — 2016-01-18 04:28:14 UTC

1. Electric charge

sukeshkamath — 2016-01-18 05:32:03 UTC

An object can store electric charges that cannot flow. These charges are called STATIC CHARGES.
The atoms of all substance contain both negative and positive charges.
The positive charges, called protons, are in the nucleus of the atoms. The negative charges, called electron, move in orbits round the outer part of the atoms.
If the atom is neutral ( Uncharged ), the number of protons and the number of electrons are the same.
The protons are fixed. Only electrons can move.

2. Attraction and Repulsion

sukeshkamath — 2016-01-18 05:36:16 UTC

There are two types of electrical charges: positive and negative.

like charges repel
unlike charges attract.
Charges are measured in units called COULOMBS.

3. Experiments to show the production and detection of electrostatic charges

sukeshkamath — 2016-01-18 05:39:19 UTC

CHARGING BY FRICTION.

Rub a plastic ruler with a piece of cloth and then hold it near some tiny pieces of paper.The rubbed plastic ruler attracts the pieces of paper.

Rub a balloon with a piece of cloth and then hold it near ( but not touching) a thin stream of water from a tap. the rubbed balloon attracts the stream of running water.

Because of friction with the piece of cloth, the plastic object have been charges with static electricity

4. Electric field as a region inwhich an electric charge experiences aforce.

sukeshkamath — 2016-01-18 05:47:19 UTC

Electric field is a region where a small charge experiences and electric force

The direction of electric field line gives the direction of electric force on a free positive charges.
Positive charges move in the direction of the arrow, while negative charges ( electrons ) move in the opposite direction.
The field lines start at positive charge and end at negative charges.
The field lines do not cross one another.
The density of field lines represent the strength of the electric field.

5. Charging by induction

sukeshkamath — 2016-01-19 05:25:41 UTC

Definition of Induction- Electrostatic induction is a process whereby a conductor becomes charged when a charged body is brought near it but not in direct contact with it.

charging by induction

sukeshkamath — 2016-01-19 05:30:51 UTC

6. Electrical conductors and insulators

sukeshkamath — 2016-01-19 05:33:05 UTC

Conductors - are materials that allow electric charges to flow through them easily.

eg - metals, graphite, ionised gases.

Insulator- are materials that do not allow electric charges to flow through them easily.

eg- plastic, rubber, glass, wood

Charged object and neutal object

sukeshkamath — 2017-07-20 01:16:04 UTC

Any charged object - whether positively charged or negatively charged - will have an attractive interaction with a neutral object.