study of electricity as a physical phenomenon begins even at school.Many teachers, in order to simplify understanding of the disciples of the material, resorting to a comparison of electrical current in a conductor with the movement of fluid through the pipe.Even though this comparison is an approximate, schematic nevertheless manages to describe the processes associated with the phenomenon of electricity in general and of electric current in the conductor in particular.But, in practice, it is much easier to learn the ins and outs of this vast section of physics, if you just consider the actual processes taking place without trying to find their counterpart in the world of mechanical phenomena.
To describe the electrical phenomena in the conductors, using a set of different values and parameters.Of course, for the practical application of electricity we are interested in the power of the current, but to determine this parameter will have to meet other basic characteristics of the flow of electricity in a conductor.
Force is one of the important characteristics of the electric current.By its physical meaning, it shows the amount of electricity (the charge) which transmits the electrical circuit at a time.For this taken into account the amount of electric charge passing through the cross-section per unit time.In mathematical form, this value appears as a pendant (Cl) divided into second (s).The unit of measurement of current value is taken amperes (A).
next parameter that is taken into account when the calculated output current is the voltage.Given that the electrical current - is the orderly movement of particles having the charge to create the movement necessary to have an electric field.Thus, to determine the value of voltage calculated current ratio works in a specific portion of the chain to the charge flowing through it.The unit of voltage, it was decided to take the volt (V), which is the ratio of physical units of work per unit charge J. Cl.
using an ammeter connected in series to a circuit that determines the magnitude of the current, and a voltmeter connected in parallel - stress.Output current is already determined analytically by multiplying effect on stress.Considering previously adopted definition of physical parameters, we obtain power unit J / s or one watt (W).In practice we have seen an example of calculation in the ideal case in which the determined DC power.
's just often in everyday practice we have to deal with three-phase current.We determine the capacity of the three-phase current as the sum of the power of each individual phase.Given that each of them operates on AC power, the calculation of the power factor is added to the load power factor cos j.
calculate the total output current for different ways to connect the load to three-phase current (and we know there are two - triangle and star) that after a simple mathematical formula for calculating the transformations in both cases took the same view.To the product of voltage on the power line current and load power factor cos j added factor equal to the square root of three (or in an approximate calculation of 1.73).
examining the concept of "current power" should be reminded of the existence of its two main types.For typical active electric power conversion into other forms of energy.She may be light, thermal, mechanical and others.To measure used watts, kilowatts, megawatts.
When considering the reactive energy mean value, which is characterized by an electrical load, created by consumers of energy fluctuations of the electromagnetic field.Often, this type of energy is characteristic of the engine.As the units take volt - amperes reactive (var).
