Electricity: Static Electricity

Static electricity occurs when there is an accumulation of electric charge on the surface of insulating materials.
It results from the transfer of electrons between materials that are in contact with each other. The material losing electrons becomes positively charged, while the material gaining electrons becomes negatively charged.
Some examples of static electricity include the ‘shock’ experienced when touching a metal doorknob after walking on a wool carpet, or the attraction of small paper pieces to a plastic ruler that has been rubbed on a wool sweater.
Unlike current electricity, which moves and creates an electric current, static electricity stays in one place.
Static electricity may produce sparks if the electric field becomes too high, this can occur when the concentration of charge becomes large enough. A familiar example of this phenomenon is lightning.
The laws of static electricity are governed by Coulomb’s Law, which states that the force of attraction or repulsion between two charged bodies is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.
Electrostatic induction happens when an electrically charged object is brought near a neutral one, causing a redistribution of charges in the neutral object. The near side of the neutral object gets an opposite charge due to induction, leading to an attractive force between the charged and neutral object.
Static electricity can be discharged by providing a conductive path for the charge to travel to ground. This is why touching a charged object can result in a shock: the charge is moving from the object to you, then to ground.
Static electricity has many uses in everyday life and industry. For example, the static charge can be used in photocopiers and paint sprayers to ensure even distribution of particles. On the other hand, it can be a hazard, causing sparks in flammable environments.
In order to prevent unwanted static electricity, objects can be ‘earthed’ by providing a direct physical connection to the earth, which allows for the static charge to safely discharge.