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Static Electricity is the electricity at rest. Static charge is generated due to "Tribo electrification" i.e. due to friction (Tribo means friction, Greek word).
When a material is rubbed against itself or another material and then separated, due to friction the outer electrons acquire sufficient energy to jump into the conduction band. Thus one material tends to strip electrons form the another, as a result, the host material becomes negatively charged due to excess of electron & the other material becomes positively charged due to lack of electrons. This gives rise to electrical potential difference between the two materials.
The potential of the charge on the object depends not so much on the amount of charge resides and its capacitance to ground. For a given amount of charge, the smaller the surface containing it, the larger the potential.
If the charge is generated in conductive material, it will be equally distributed over its surface and can be drained of easily by proper grounding but if the material is INSULATOR, due to high insulator Resistance, the charge will remain there at rest and cannot be drained off by grounding one end of object.
Thus we can say that "INSULATOR ARE GENERALLY STATIC GENERATORS"
| To summarize, static charges are principally generated by the imbalance in the molecular structure of materials, due to three causes : - | |
| FRICTION | Rubbing |
| SEPERATION | Seperation after intimate contact. Here the amount of charge depends on material, area in actual contact, speed of seperation and ambient humidity |
| INDUCTION | The Electrostatic fields radiating form static charges also cause charge generation (of opposite polarity & same potential) in other surface without making contact |
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