In science, the amount of electricity passing through any cross-section of a conductor per unit of time is called the current intensity, abbreviated as current. Usually represented by the letter I, its unit is the ampere (Andrei Marie Ampere, 1775-1836, French physicist and chemist, with outstanding research achievements in electromagnetic interactions and contributions to mathematics and physics. The international unit of current, the ampere, is named after its surname), abbreviated as "ampere", with the symbol "A", also referring to the directional movement of charges in a conductor. The free charge in a conductor undergoes regular directional motion under the action of electric field force, forming an electric current. The electromotive force of the power supply forms a voltage, which in turn generates an electric field force. Under the action of the electric field force, it is at an electric microampere（ μ A) 1A=1000mA=1000000 μ A. According to electrical regulations, the direction of directional flow of positive charges is the current direction. The micro expression of current in a metal conductor is I=nesv, where n is the number of free electrons per unit volume, e is the amount of electron charge, s is the cross-sectional area of the conductor, and v is the charge velocity. There are many types of carriers in nature that carry charges, such as movable electrons in conductive bodies, ions in electrolytes, electrons and ions in plasma bodies, and quarks in hadrons. The movement of these carriers forms an electric current