Lightning is the most common and powerful example of static electricity. This article gives a detailed insight on how does static electricity work.
Whenever there is an imbalance between the number of positive charges and negative charges in an object, it results in static electricity. The accumulated charges are discharged through a circuit i.e., static electricity. Rubbing a balloon against our clothes makes it stick due to static electricity.
Why does static electricity make things stick?
Materials are made of atoms. They develop static charges when transfer of electrons happen from one material to another. Whenever objects are rubbed, one of them loses electrons and becomes positively charged, while the other might gain electrons and becomes negatively charged. Opposite charges attract each other and this static electricity makes objects stick together.
When a balloon is rubbed with your hair, it gets charged. Now as we bring the balloon near a neutral object like paper, the electrons in the option move away from the balloon, while protons get attracted to it. Thereby, the object develops a slight positive charge and gets attracted to the negatively charged balloon due to which the balloon sticks to the object.
Similarly, socks taken fresh out of a dryer stick together. A ruler rubbed with hair when brought near small bits of paper makes paper to stick to the ruler, even for a short time interval.
Can static electricity hurt you?
Static electricity, in general, is not dangerous. The momentary shocks and pops we experience in certain situations are due to the discharge. These momentary discharges won’t hurt us.
However, in certain environments, like grain storehouses, dust get accumulated that a small spark might ignite them and can result in explosions. Also, static charges can damage the semiconductors in electronic devices. People handling gasoline should take great care to avoid static buildup as the fuel is flammable and may result in explosions.
The most dangerous situation is the static discharge in lightning. The consequences of being struck by a lightning can be very deadly, as it might cause severe even at the first strike. The high voltage can impart death to living beings including humans.
What happens during static electricity?
Materials build up electric charges when electron transfer takes place between objects. This build up of electric charge is static electricity. Electron exchange can happen due to contact (friction), heat, pressure or through induction. Positive charge is accumulated when objects lose electrons and negative charges when they gain electrons.
Objects with loosely bound electrons get transferred when it is rubbed with another material. This buildup of charge is due to friction/contact. Similarly applying mechanical stress and heat induces charge in certain crystals. Electrostatic induction is another method of inducing charge in materials.
In electrostatic induction, a charged object is brought close to a neutral object. The region near to the charged object will get oppositely charged and the other end will get charged similar to the charged object. This charge separation is a form of static electricity.
How do photocopiers use static electricity?
Photocopiers are machines that use static electricity to make paper copies of documents and other visual images quickly and easily.
A photocopier comprises a photoreceptor drum, corona wires, lamp and lenses, toner and fuser. In the photocopier a latent image is created in the form of electric charges on the drum surface using the light-induced conductivity of the drum.
The corona wires can generate a field of positive charges on the drum and the copy paper when a high voltage is applied. The paper to be copied will be placed downwards on a sheet of glass. The image of this paper will be projected using static electricity on the positively charged drum. The toner is a powder and is negatively charged. Printed text and images on copy paper are created by the toner. Being negatively charged, the toner gets attracted to the drum (positively charged) where the image is projected.
The drum rotates and rolls against a fresh paper where the toner is then transferred and hence, a black and white copy of the original paper is obtained.
How Does Static Electricity Work: Frequently Asked Questions
Explain lightning as an example of static electricity.
Lightning is a natural phenomena that is a perfect example for charge discharge through static electricity.
When cold air and warm air meet, there are chances of occurrences of lightning. The cold air consists of ice crystals while the warm air comprises water droplets. During a storm, the crystals and droplets rub against each other and results in the accumulation of charged clouds. The top region of the clouds will be accumulated by positive charges while the bottom region by negative charges. When the bottom charge gets enough strength, energy is let out by the clouds and lightning occurs.
The released energy moves towards a place of opposite charge. The discharge may be from one cloud to another or from cloud to the ground. One lightning stroke is sufficiently strong enough to cause damage to materials and even fatal to living organisms.
Give some applications of static electricity.
Static electricity is used in variety of applications in real life. Some of them are:
- Photocopiers and printers
- Pollution control
- Air fresheners
- Painting cars
Photocopiers and printers
Printers and photocopiers make use of static electricity to attract the ink to the paper and hence make a copy of the required document.
Static charge is applied to dust or dirt particles in the air and hence to collect these particles on a plate. Such devices are known as electrostatic precipitators that find applications in several factories and play a major role in pollution control.
Factories apply electrostatics to avoid pollution from smokestacks. The smoke is given an electric charge and as it passes it clings to the electrodes of opposite charge, thereby preventing the smoke from reaching the atmosphere.
Air fresheners used in household or offices works based on the same principle of smokestack pollution control by creating static electricity. The dust and smoke particles get charged and would be attracted to the oppositely charged plate in the air freshener.
Certain automobile manufacturers deploy static electricity to paint cars. The paint is given a charge and they get attracted to the car in a similar manner as the balloon sticks to a wall.