opened electromagnetic oscillations, can be said to some extent by chance.Free and forced vibrations found their wide application in our daily lives.Electromagnetic oscillations are used in a variety of technical devices, including in the mass media.Variables technical currents - it is also the electrical oscillations.Even the phenomena of light - is electromagnetic waves.We'll talk about them in more detail.
Under fluctuations understood processes or movement, characterized by the stipulated time repeatability.Such processes are widespread.The physical nature of oscillatory processes can be varied.Accordingly, distinguished electromagnetic, mechanical and other vibrations.
Among the various electrical phenomena free and forced electromagnetic oscillations occupy a special place.Under electromagnetic oscillations understand fluctuations in magnetic and electric fields, accompanied by a periodic change in the voltage, current and charge.In order to initiate and maintain the electromagnetic waves used oscillating circuit.
Forced vibration - these oscillatory processes that are caused by external forces on the system.
Forced oscillations have their own distinctive feature - they are not fading character.Their frequency is the frequency of the periodic external influence on this oscillating system.However, we must distinguish between such oscillatory motion of the self-oscillation.When self-oscillations in the supposed mechanism "provided" in a certain reservoir of energy in time with their vibrations, small portions of energy to maintain their own sustained oscillations.Thus, when self-oscillation system "pushes" itself.When forced vibrations of the system takes a push from the outside force.
frequency of these oscillations coincides with the frequency of the external force.They do not arbitrarily set the amplitude, as in the free vibrations, and set itself.The value depends on the ratio of the amplitude of the external force and frequency of their own.
Forced oscillations characteristic phenomenon of electrical resonance.Under him the amplitude of forced oscillatory motion is maximized.The oscillation amplitude at a resonance must be infinitely large.In fact, when it displaced the amplitude of electromagnetic waves is finite.With a small resistance in the resistance at resonance is important.This makes the amplitude of vibrational motion in resonance final.At a higher resistance in the system is below a maximum amplitude at the resonance point.
AC - it is nothing like the forced electromagnetic oscillations that occur in the process of rotation within the frame of the magnet or the magnetic field rotation in the frame as a result of electromagnetic induction.The alternator is an alternating current source.
Electric lamps, vacuum cleaner, refrigerator, TV, etc., used in our homes, work on the basis of the energy of electromagnetic waves.In their application based operation of electric motors, which drive the machines, etc.
In these examples use alternating current, which is in the electrical power circuit acts as a result of excitation of forced oscillations.
emphasize that free and forced vibrations differ from each other in that one carried out without external influences thanks to the energy that is stored in the circuit, and the other caused by external influences on the system.
