We all know that in order to turn on the lights, press the rotary key switch, click on them.Click - and the lamp lights up, illuminating all around.Typically, few people think about the processes occurring in these moments.In fact, many researchers have devoted years trying to figure out what the voltage and current.
analogy with fluids meaning of the word "current" is known to all - is directed motion, flow.With respect to electricity, it is an orderly movement of negatively and positively charged particles.It is important to bear in mind that it's not just about the electrons of atoms and their loss.The electron charge is negative, but in the ions (atoms mentioned) - positive.Understand what is the voltage, the following example will help.
imagine a simple scheme: the incandescent lamp, the switch is connected to the rupture of one of the two summing up the wires, and power supply.To lit the lamp, it is necessary, first of all, to understand what is stress and what is the difference of the natural motion of the particles and forced.
metal wire is made of atoms, which is constantly going on the natural movement of electrons.However, on the current in this case it is not, since there is a disordered (chaotic, undirected) moving them.Particles "makes" move in the right direction of the electric field.It can serve as a source of power generators, chemicals and so on. In the current strength and the field, his calling, there is a direct correlation: the growth of the electric field and the current increases.
Generally, current - is the number of elementary particles, "passed" through a conductor per unit of time.The total charge who managed to pass the electrons is measured in coulombs.Hence, the unit of current, the ampere, is in charge of 1 coulomb passing through the wire in 1 second.
However, without understanding what is stress, it is impossible to determine the number of current dependence on the electric field.In fact, the field is a force which makes each electron (or pendant) to move in the desired direction.However, since the value of the field is different in each point of the conductor, it was decided to characterize the operation of moving the charge, rather than an abstract force.
Thus, the voltage - a potential difference on opposite ends of the conductor connected to the source of the EMF.Voltage is measured in volts.For this purpose a special device - a voltmeter.It is connected parallel to the load: for example, the above two probes of the voltmeter connected to the respective two terminals of the lamp.This allows you to measure the field strength between these points.
To facilitate understanding can imagine itself the "behavior" of charged particles in a conductor.Electronic, as already mentioned, has a negative charge, therefore, attracted to particles of the opposite charge sign.The higher the concentration of ions from any pole, the more free electrons in a conductor (because they are - of the atoms).This difference between the ratio of "-" and "+" is the voltage.
field (voltage) is generated in power plants.Based on the law of electromagnetic induction, the conductor, intersecting lines of the magnetic field, an electromotive force.Just connect the load and create a chain as the supply voltage.The external power generators (water, steam, wind) drives the electromagnet, which leads its field in the windings of the EMF.Each winding forms a phase.The most widely received three-phase voltage.To create in the oscillator are present directly three windings arranged in a certain way (lagging from each other by 120 degrees).
