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Static Electricity. Definition And Examples

Static electricity. Definition and examples

Static electricity is an imbalance of electrical charges in a material.

Materials are made up of atoms with positive and negative charges. Atoms are made up of neutrons and protons in the nucleus and electrons around it. Protons are positively charged and neutrons negative.

If a material A and a material B are very close, the electrons can jump from one material to another. For example from A to B. Material A loses electrons and B gains them.

The result of this electron transfer is that Material A will have more protons than electrons. That is, it will have a positive charge. Material B, with more electrons, will have an excess of negative charge.

Materials with a different charge (positive, negative) attract each other. Those with the same load repel each other.

The charge remains until it can be removed by an electric current or electric shock.

What is the difference between ordinary electricity and static electricity? In statics, the flow of electrons is not constant. In ordinary electricity electrons flow constantly through cables and conductive materials.

In the subsequent separation of these bodies, each of them retains its electrical charge. With the increase in distance between them due to the work in progress to the separation of charges, the potential difference increases and can reach tens and hundreds of kilovolts.

Examples of static electricity

Static electricity is widespread in everyday life. 

  • Rubbing with a wool mat. If a wool mat is spread on the floor, then by rubbing, the human body can receive a negative electric charge.
  • Electrification of a plastic comb. With this example, by rubbing the comb with the hair there is an electron transfer. The different charge between one and the other makes them attract.
  • Rubbing a balloon with a wool sweater. If we rub an inflated balloon on a wool sweater it is statically charged. If we approach it to the ceiling, it remains stuck because they attract due to the difference in loads.
  • Electrified hairs. If we touch a balloon with the hair, the hair will seem to take on a life of its own.

The electrostatic discharge passes at very high voltage and extremely low current intensities.

On a dry day, the comb example can lead to the accumulation of a static charge with a voltage of tens of thousands of volts. However, the current of your release will be so small that it often cannot even be felt.

Electronic components

On the other hand, high voltages can be dangerous for elements of various electronic devices: microprocessors, transistors, etc.

Therefore, when working with electronic components, it is recommended to take measures to avoid the accumulation of static charge.

Lightning from storms

As a result of the movement of air currents saturated with water vapor, storm clouds form. Storm clouds are carriers of static electricity. Electric discharges form between clouds with opposite charge or, with the ground.

When a critical potential difference is reached, a lightning strike occurs between the clouds, on the earth, or in the near-cosmic layer of the planet.

In addition to lightning, storm clouds can cause dangerous electrical potentials in isolated metal objects due to electrostatic induction.

What does static electricity generate depend on?

The potential difference resulting from the contact surfaces depends on a number of factors: 

  • The dielectric properties of materials.
  • The values ​​of their mutual pressure on contact.
  • The relative humidity and the temperature of the surfaces of these bodies.
  • Weather conditions.

Electric shocks can form due to some electrical conductivity of moist air. With an air humidity of over 85%, virtually no static electricity is produced.

What produces static electricity?

Electric charges can pass from one body to another for the following reasons:

  • By contact. Triboelectric effect Electrons can jump between materials in contact. Materials with loosely bonded electrons tend to lose them, while materials with poorly filled outer layers tend to lose them.
  • By pressure. It is the piezoelectric effect. The applied mechanical stress generates a charge separation in certain types of crystals and ceramic molecules.
  • By heat. Pyroelectric effect. Heating generates a charge separation in the atoms or molecules of certain materials. The heat and pressure response are thermodynamically related.
  • By load. Electrostatic induction. An electrostatic charged object approaching a neutral object causes electrons to pass from the charged object to the neutral one.

Summary

Static electricity is the passage of electrons from one material to another. This transfer generates a variation in the electrical charge of the materials.

The difference between home electricity is that in home electricity the electrons flow continuously.

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Published: January 23, 2020
Last review: January 23, 2020