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Zakon Oma - eto glavnyy zakon elektrika! Ni odin raschet elektricheskoy skhemy, kakoy by slozhnoy ona ne byla, ne obkhoditsya bez nego. Lyubaya elektricheskaya ili elektronnaya skhema kharakterizuyetsya vsego tremya osnovnymi parametrami. Pervyy - eto napryazheniye na soprotivlenii nagruzki. Vtoroy - eto samo soprotivleniye nagruzki. I tretiy parametr - eto sila toka, protekayushchaya cherez nagruzku. Zakon Oma dlya uchastka tsepi pozvolyayet opredelit' lyuboy iz trekh neizvestnykh parametrov pri zadannom znacheniye ostal'nykh dvukh parametrov. Uproshchenno yego mozhno poyasnit' tak: s postom soprotivleniya nagruzki, elektronam stanovitsya slozhneye proyti cherez neye, poetomu elektrony otdayut bol'she energii na preodoleniye soprotivleniya; sootvetstvenno tem men'shiy tok budet protekat' v tsepi.
Takzhe na praktike shiroko primenyayetsya zakon Oma dlya polnoy tsepi. Pod polnoy tsep'yu v dannom sluchaye ponimayut elektrodvizhushchuyu silu EDS istochnika pitaniya, yego vnutrenne soprotivleniye i soprotivleniye nagruzki. S uchetom eto sila tok v polnoy tsepi budet neskol'ko nizhe, za schet dopolnitel'nogo padeniya napryazheniya na vnutrennem soprotivlenii. Poetomu chashche vsego istochnika pitaniya kharakterizuyut ne po EDS, a po napryazhenii.
Imenno blagodarya zakonu Oma elektrichestvo poluchilo svoye dal'neysheye razvitii, a ot nego obrazovalis' tselyye otdel'nyye napravleniya: elektronika, elektrotekhnika i t.p. Pervyye opyty Om provodil primenyaya magnitnuyu strelku dlya opredeleniya sily toka. Vposledstvii uchenyy prishel k tomu, chto otkloneniye strelki prya proportsional'no velichine napryazheniya i obratno proportsional'no soprotivleniyu.
Ohm's law is the main law of an electrician! No calculation of the electrical circuit, no matter how complex it was, can not do without it. Any electrical or electronic circuit is characterized by only three basic parameters. The first is the voltage on the load resistance. The second is the load resistance itself. And the third parameter is the current that flows through the load. Ohm's law for a chain section allows one to determine any of the three unknown parameters with a given value of the remaining two parameters. Simplified it can be explained as follows: with the load resistance post, electrons become more difficult to pass through it, so electrons give more energy to overcome resistance; so the smaller the current will flow in the circuit.
Also in practice, Ohm's law for the complete chain is widely used. Under the full circuit in this case is understood the electromotive force of the power supply EMF, its internal resistance and load resistance. With this in mind, the current in the full circuit will be somewhat lower, due to an additional voltage drop on the internal resistance. Therefore, most often the power source is characterized not by EMF, but by voltage.
It is thanks to Ohm's law that electricity has been further developed, and whole lines of it have been formed from it: electronics, electrical engineering, and so on. The first experiments were carried out using a magnetic needle to determine the current. Subsequently, the scientist came to the fact that the deviation of the arrow is directly proportional to the magnitude of the voltage and inversely proportional to the resistance.