The understanding of electricity, the understanding of electricity

The understanding of electricity is to pay attention to the safety of electricity. Electricity is something that nature has, and humans just use it.

Electricity is a phenomenon of separation

For those who use electricity, they may have only learned this principle in the conductivity of junior high school physics.

The knowledge of electricity is as follows:

Electricity is one of the sub-disciplines of physics. His research focuses on the formation of "electricity" and its applications. In the West, the word "electricity" is derived from the Greek word amber, and in China it is derived from the phenomenon of lightning and lightning.

Since the middle of the 18th century, the study of electricity has been flourishing. Each of its major discoveries has led to extensive practical research, which has led to the rapid development of science and technology.

Nowadays, electricity is inseparable from human life, scientific and technological activities, and material production activities. With the development of science and technology, some research contents with specialized knowledge have gradually become independent and formed specialized disciplines, such as electronics and electrical engineering. Electricity, also known as electromagnetism, is a fundamental discipline of great significance in physics.

Electrostatics:

It is a discipline that studies the electric field generated by the stationary charge and the law of the electric field on the charge. There are only two types of electric charges, which are called positive and negative. The same charge repells each other, and the different charges attract each other. Electric charges obey the law of conservation of electric charges. Medium to do.

Charge can be transferred from one object to another, and the algebraic sum of charge remains constant in any physical process. The so-called charging is nothing but the separation or transfer of positive and negative charges; The so-called disappearance of electric charge is nothing but the neutralization of positive and negative charges.

The interaction forces between the charges at rest conform to Coulomb's law: in a vacuum, the magnitude of the force acting between two charges at rest is proportional to the product of their charge and inversely proportional to the square of the distance between them; The direction of the force is along the line between them, with the same charge repelling and the different charge attracting.

Categories: Education Academic Exams >> Gaokao.

Problem description: The various concepts of electricity have been troubled for a long time, what joules, watts, amps, volts, etc., and even always can't figure out the relationship between the various units, please advise you, thank you!

Unalumination of Yu Sun Analysis:

There are several basic formulas for understanding and memorizing these units and their interrelationships.

1.Ohm's law i = u r

where i is the current intensity, unit: ampere; u is the voltage, unit: volts; r is the resistance, unit: ohm. 1 amp 1 volt ohm.

2.Electrical work w iut, where w is the electrical work, that is, work, unit: joules. 1 joule 1 amp * volts * sec.

3.Electrical power p w t, where p is the electrical power in watts. 1 watt 1 joule second.

In fact, except for the units of current intensity, voltage and resistance, the other units are the same as the units of mechanics (e.g., the unit joule of work, the unit of watts of power beam chain).

Electricity has greatly improved people's lives: farewell to oil lamps, the use of various electrical appliances, the rapid development of transportation, etc.;

It is characterized by fast speed (close to the speed of light), which is easy to transmit, but it is invisible and intangible, which brings convenience to human beings and has great dangers.

The function is that it can be converted into light energy, heat energy, power, and so on.

Electricity is a natural phenomenon, and in ancient times people discovered its existence through 'lightning'. In ancient China, the ancients believed that the phenomenon of electricity was generated by the stimulation of yin and yang. "Vocabulary" has "thunder from the back, electricity from the shen."

Yin and yang become thunder with thinness, and electricity is electricity with catharsis." In the ancient book "On Balance", there is a record of static electricity, and the mystery of electricity has always attracted curious people to explore. After a long process, it was not until the 18th century that the American scientist Benjamin Franklin discovered that lightning in the sky was the same thing as electricity on the ground.