Ohm's law for the complete chain

Ohm's law is one of the basic postulates of physics. The general formula, which is valid for both the complete circuit and its section, indicates that the current strength is equal to the partial value obtained as a result of dividing the value expressing the voltage in volts by the value expressing the current in amperes. This dependence shows that as the resistance decreases, the current increases. The question arises: is it possible to obtain the maximum current by reducing the resistance to zero? Practice shows that this is impossible. Ohm's law for the complete circuit indicates that the voltage should be divided by the total, total resistance, calculated as the sum of the external resistance and internal resistance, depending on the current source. It is not possible to reduce the internal resistance of the system to zero. Otherwise, the probability of a battery explosion is very high.

What is the internal and external resistance, which Ohm's law says for the complete chain? If, for example, a light is connected to the circuit, then the external resistance of this light bulb. Internal resistance always comes from the battery, that is, it is formed inside the system itself. If instead of a battery a galvanic cell is used, Ohm's law for the whole circuit takes into account the resistance of the electrolyte solution and the electrodes. If the external resistance is several times smaller than the internal one and the circuit is closed, a short-circuit current flows through it. This is the maximum value of the current that can pass through this circuit. The current sources in the cars show the values of the short-circuit current strength , which are critically dangerous for life. For security reasons, they are connected to external battery devices that have sufficient resistance to prevent a tragedy.

With a series connection, the total internal resistance of the circuit is calculated by adding the resistances of each of the current sources. With parallel connection, the voltage on each of the branch sections has the same value, and the current in the unbranched circuit is calculated by adding the values that show the ammeters on each of the sections connected in parallel. The current source located on the circuit section has no effect on the parallel section connected to it.

Where are the Ohm laws applied for the complete chain? They are mainly used to calculate the current in linear electric circuits of direct current. To perform the calculations correctly, it is necessary to remember the postulates of Kihgof. First, the algebraic sum of the current forces at the site is zero. Secondly, the product of the algebraic sum of the current forces in any closed loop of the branched circuit and the resistance of the sections of a given circuit is always equal to the algebraic sum of the voltage found in the circuit.

Under what conditions, how and when was Om's law for the complete chain discovered? The Swiss researcher Georg Simon Om came to the empirical formula known to the whole world today. He studied the magnetic action of the current and experimented with various generators, using conductors from different metals and alloys in his experiments. Om was the first physicist to notice the influence of temperature on conductors. Ohm's law for the complete chain was recognized by the scientific community not immediately. The first scientists who appreciated this law were Russian researchers Jacobi and Lenz. The American J. Henry later compared the formula expressing Ohm's law for the complete chain, with lightning in the middle of a deserted gloomy room, and the German professor E. Lommel called the opening "a bright torch in the field of electricity."