The electrical circuit assumes the presence of a number of different components. Capacitors and inductance elements are included in the circuit to obtain the most diverse effect. Active resistance is present in the form of separate resistor elements and as the resistance of the connection wires. The physics of the influence of this component of the circuit on the laws of the flow of electrical phenomena has been studied quite thoroughly, and differs little from the nature of the flow of electric current, whether under the influence of an alternating or constant voltage.
The active resistance in the AC circuit works in the same way as in the DC voltage mode. A completely different thing is the elements of capacitance and inductance. If the DC component of the circuit in which the capacitor is connected is completely absent, then the inductance coils have no effect on it. The direct current flow in the inductance variant is affected only by the active resistance of the coil.
The situation is completely different when describing electrical processes in an alternating current circuit . Capacitors become conductors, and inductors (chokes, transformer windings, etc.) acquire inductive resistance, and it in turn plays a much more important role, and resistance is often simply not taken into account.
But, nevertheless, the need for accurate calculations requires taking this component into account. To begin with, in order to understand how the active resistance of a coil is combined with inductive, it is necessary to consider in general terms the structure of a standard inductor.
In the role of a component of the electric circuit, this device is nothing but a bipolar element of a wide variety of electrical, electromechanical and electronic systems and devices. As the main parameter, it uses the value of the intrinsic inductance. The same in turn depends only on the geometric dimensions and materials of manufacture. Neither current nor voltage affects the magnitude of the inductance. The use of inductors is found in filters to suppress noise, their use allows smoothing ripples, and the coil can accumulate energy, which is widely used in the design of oscillatory circuits.
In order to analyze what effect the active resistance has on the operation of the inductor, one should consider an alternating current circuit with the only element, which is the inductor. Having calculated the active and inductive resistance, it would seem that the simplest way to calculate the total value is to add them modulo.
But with these quantities, the situation is not as simple as it would seem. Omitting the theoretical justification, we describe the practical use of the method of summing the active and inductive resistances.
To find the total indicator, we build a rectangular triangle. One of its legs is active resistance, and the other is inductive. The hypotenuse will be equal to the total resistance of the circuit, which according to the definition will be equal to the square root of the sum of the squares of the active and inductive resistances.
The calculations carried out in this way carry more accurate information about the processes taking place in an alternating current circuit, the elements of which are inductors. In the formula of Ohm's Law, we have the opportunity to use the magnitude of the impedance. In the future, it should be noted that a significant active resistance when compared with inductive can affect the phase shift between current and voltage. That is why in the manufacture of chokes, a core design is widely used, which gives significant advantages to inductive resistance.