Static electricity is a familiar electric phenomenon through which charged particles are transmitted from one system to another. When two bodies are rubbed together, notably if the bodies are insulators and are surrounded by dry air, the bodies gain equal and opposite charges. Ultimately, an attractive force is developed between them. The body that dropped electrons will possess a positive charge, and the other body will possess a negative charge. The force is basically the attraction between opposite charges. The characteristics of this force are encapsulated in the mathematical relationship called Coulomb’s law.
A static charge can be generated whenever two bodies touch each other which have worn and separated (at least one of the bodies has a high resistivity to electric current (an electrical insulator). The impacts of static electricity are quite familiar to us because we can hear, feel and perceive the spark as the excess electric charge is neutralised when brought near to a relatively big electrical conductor (like a grounding path) or an area with a surplus charge of contrasting polarity (negative or positive). The familiar process of a static shock, specifically the phenomenon of electrostatic discharge, is produced by the neutralisation of a charge.
Here are some of the familiar instances of static electricity in daily life.
Rubbing a Stick with a Cloth
When a stick is rubbed with a cloth, it generally tends to grow a particular charge on it. The nature of the charge relies upon the characteristics of the material from which the rod is made of. A plastic stick, when rubbed with a cloth, tends to generate a negative charge. In the case of a glass stick, it tends to generate a positive charge. When these charge sticks are brought close to hanging cotton yarn balls, an attraction or repulsive force is experienced around them. The electrostatic force allows us to conclude the charge that is present on the cotton yarn ball.
Electrically Activated Comb
When we comb our hair, the caressing and rubbing motion of the comb over our hair generates a considerable amount of activated charge on the comb’s teeth. If this activated comb is subjected to light objects such as paper bits, it forces the paper bits to attract with the comb. This phenomenon is a clear exhibition of electrostatic force arising between the paper bits and the comb.
Dust on Television Screens
Electrical devices are notorious for their ability to attract huge amounts of dust into them. The most common device is the television. The wandering dust particles get easily polarised by the tv screens. Because of this, the dust particles develop a charge on them. Such charged particles easily stick to the television screens. This is the fundamental reason why a film of dust gets settled on the tv screens just minutes after removing previous layers. Such interaction between the screen and the dust particles is called the electrostatic interaction. There is a list of materials called the triboelectric series, which ranks substances according to their ability to lose or gain electrons. If we move our hands close to the screen, we can instantly sense the electrostatic force around the screen.
A photocopy machine is one of the important best applications of static electricity. The paper which is supposed to be copied is placed over the glass screen. The image of the targeted paper is sent to a photoreceptor drum that is positively activated. The ink powder is typically activated with a negative charge—the drum rolls against the printable paper on which the image is needed to be generated. Then, the ink gets transported to the paper. In doing so, it successfully generated a photocopy of the original document.