Electricity is a term used in a physics course. Let us analyze the definition of this physical quantity, the features of the appearance, application.
Definition
What is electricity? The definition in physics implies a combination of various phenomena associated with the movement of an electric charge.
This term was introduced by the English scientist William Gilbert in 1600. He tried to explain the essence of the phenomena that occur when a magnetic compass acts on a body. It was he who in practice confirmed the existence of electrification of bodies.
Pages of history
Electricity is a phenomenon that they tried to explain already during the existence of Ancient Greece. Philosophers living in the seventh century BC found that when rubbing amber on natural wool, it acquires the ability to attract various objects.
In the seventeenth century, the German Otto von Guericke created an electrostatic machine consisting of a sulfur ball mounted on a metal rod. Such a construction allowed him to observe not only the attraction of objects, but also their repulsion.
At the end of the eighteenth century, the Englishman Stephen Gray conducted a series of experiments to transfer electric energy to a certain distance. He managed to find out that, depending on the composition of the material, the ability to conduct electric current changes.
What is electricity? The concept, essence of this physical phenomenon was explained by the Frenchman Charles Dufe. During various experiments, he received tar and glass electricity, which appear during friction against glass silk, resin on wool. In the mid-eighteenth century, Peter van Mushenbrook developed an electric capacitor called the Leiden Bank. In parallel, experiments related to the study of atmospheric electricity were conducted by the Russian scientist M.V. Lomonosov.
At the end of the eighteenth century, Coulomb discovered the law according to which electricity is the movement of charged particles.
At the beginning of the nineteenth century, physicist Oersted discovered electromagnetic interaction. He opened and closed the circuit, observing the oscillations of the compass needle located near the current conductor. Ampère found that magnetism and electricity are connected when there is no static electricity.
Faraday, using the results of the experiments of Ampere and Oersted, discovered the phenomenon of electromagnetic induction. It was he who developed the electric energy generator , consisting of a magnetized core, coil, through which electricity passed. The meaning of the word after experiments began to be associated with the movement of charged particles.
Maxwell's work became the crown of all electromagnetic phenomena. In the twentieth century, the quantum theory of electrodynamics appeared. She answered all the questions that remained with the scientists for that period of time.
What is an electric charge
We have already found that electricity is a quantity that is associated with the movement of charged particles. And what is an electric charge? It implies the ability to create an electric field around a conductor. Bodies that have the same charge are repelled, and attracted by different ones. It is with the movement of particles that an electric current is transferred inside the conductor.
Natural electricity
As a bright manifestation of electric current in a living world, lightning is considered. Its electrical nature was established in the eighteenth century. It was lightning that caused numerous forest fires. The potential difference that arises between the layers of the atmosphere and the Earth's surface is 400 kV.
The processes taking place in the nervous system are also associated with the passage of an electric charge. For example, during an increase in tension on the cell membrane, a surge in voltage is observed, which in biology is considered a nerve impulse. With it, you can transfer information from one cell to another. Fish use electricity to search for prey underwater, as well as to protect themselves from enemies.
For example, South American electric eel can generate discharges of electricity up to five hundred volts. Lampreys and sharks can use electricity to detect prey. Special electrical receptors capture the fields of other organisms.
Conclusion
Electrical experiments have contributed to technological progress. It is on the basis of electric current that a variety of devices are used that are used for a person’s daily life, in science and technology.
In order to fully satisfy all the demands that reality puts forward to electricity, powerful current generators have been developed. Their work is based on the theory of electricity and magnetism, discussed above.