From birth and throughout life, electrical appliances surround. These include: household appliances, lighting of our homes and streets, mobile communications, even modern cars are switching to electricity. All these devices consume electric current, some take it from electric networks, others draw from batteries and accumulators, and others from alternative sources of energy (“windmills”, solar panels, etc.). But how many people know what a unit of current is and what is electric current? In this article we will answer these questions.
Let's start with the basic concepts. An electric current is called directed ordered motion in a conductor of charged particles. Consider the conditions for the existence of current:
- the presence of free electrons in a metal conductor;
- the presence of an electric field (such a field is created due to the current source).
Now we turn to the consideration of such a concept as a unit of measurement of current strength. This scalar value is denoted by the Latin letter I. The unit of current is determined by the ratio of the charge q passing through the cross section of the metal conductor to the time interval t during which the electric current passed through the conductor. Accordingly, the formula has the following form: I = q / t. A unit of current indicates what charge passes through the cross section of the wire per unit time.
Everything is pretty elementary. Now let's look at what generally accepted units of measurement of current strength exist. To do this, just look into the international system of units (SI). It follows from it that the unit of measurement of amperage is Ampere. This unit got its name in honor of the French physicist-mathematician Andre-Marie Ampère (1775-1836). He introduced such terms as electrodynamics, electrostatics, solenoids, EMF, galvanometer, electric current, voltage and others. The scientist A. M. Ampere predicted the emergence of such a science as “cybernetics”, he became the pioneer of the mechanical interaction of conductors with electric current, introduced a rule for determining the directions of current.
Now let's try to analyze this concept from the point of view of elementary physics. To do this, it is necessary to illuminate the properties of the passage of electric current through two parallel conductors. If charged particles move along two wires in the same direction, then such conductors will begin to attract, and if the particles move in different directions, then the conductors will tend to push off from each other. For a unit of current strength of one ampere, it is customary to consider such a force due to which two parallel wires of one meter long, spaced one meter apart, will begin to interact with a force of 0.0000002N.
To summarize, we say that knowledge of such a concept as current strength will help determine the amount of energy consumed by electrical devices. Thanks to this, it is easy to calculate the wiring load in your home and, accordingly, to protect your home from fire or damage to electrical equipment, which often occurs when the distribution of household electrical appliances is incorrect.