# Electric Force

Electric Force - As everyone knows that matter is made of atoms. These atoms are made up of minute particles or I say fundamental particles electron, proton etcetera.
• Protons are +ve Charge.
• Electrons are -ve Charge.
Now learn this specific term I have mentioned below.

• Positive Charge with Postive Charge  =  Repel Each Other.
• Negative Charge with Negative Charge = Repel
• Positive Charge and Negative =Attract
• Negative and Postive Charge =Attract

It is similar to magnets.

Now, there is a primary property of elementary particles ( like electrons, protons, etc) of which all the objects are made up of,  exert a strong electric force (s) of attraction or repulsion on each other.

## Electric Force

All matter is made of atoms. An atom consists of a small central nucleus containing protons and neutrons, around which revolve a number of electrons. In any piece of matter, the positive proton charges and the negative electron charges cancel each other and so the matter in bulk is electrically neutral.

### Electic Force in Action

The electrons of the outer shell of an atom are loosely bound to the nucleus. The energy required to remove an electron from the surface of a material is called its 'work function'.
•  When two different bodies are rubbed against each other, electrons are transferred from the material with a lower work function to the material with a higher work function.

• For example, when a glass rod is rubbed with a silk cloth, some electrons are transferred from the glass rod to silk. The glass rod develops a positive charge due to a deficiency of electrons while the silk cloth develops an equal negative charge due to the excess of electrons.

• The combined total charge of the glass rod and silk cloth is those of still zero, as it was before rubbing i.e., electric charge is conserved during rubbing.

### Origin of Electric Force

The only way by which an electron can be pulled away from an atom is to exert a strong electric force on it. As electrons are actually transferred from one body to another during rubbing, so frictional forces must have an electric origin.

### Cause of Electric Force

The cause of electric force is the actual transfer of electrons from one material to another during rubbing.  Protons are not transferred during rubbing.
The material with a lower work function loses electrons and becomes positively charged.
As an electron has a finite mass, therefore, there always occurs some change in mass during charging. The mass of a positively charged body slightly decreases due to the loss of some electrons. The mass of a negatively charged body slightly increases due to gain in some electrons.

### Role of friction in Electric Force

• If a glass rod is rubbed with a silk cloth or a fountain-pen with a coat-sleeve, it is able to attract small pieces of paper, straw, lint light feathers, etc.

• Similarly, a plastic comb passed through dry hair can attract such light objects.

• In all these examples, we can say that the rubbed substance has become electrified or electrically charged. It is because of friction that the substances get charged on rubbing.

The property of rubbed substances due to which they attract light objects is called electricity. The electricity developed by rubbing or friction is called frictional or static electricity. The rubbed substances which show this property of attraction are said to have become electrified or electrically charged and all because of the electric field.

### Application of Electric force

The attraction and two repulsions between charged bodies have many industrial applications. Some of these are as follows:
•  In electrostatic loudspeaker
•  In electrostatic spraying of paints and powder coating
•  In fly-ash collection in chimneys.
•  In a Xerox copying machine.
•  In the design of a cathode-ray tube used in television and radar.