The characteristic of the inductive element is "straight across the traffic".
The characteristic of the inductive element is "straight across the traffic". When the current flowing through the inductor is smooth and pure DC, it is equivalent to a wire, and will not play any role (in the case of ignoring the internal resistance of the wire). When the current flowing through the inductor is AC or fluctuating DC, it will block the change of current when the current changes, making the current smoother, without sudden increase or decrease.
DC on: refers to that the inductor is closed to the DC. When the resistance of the inductor coil is ignored, the DC current can pass through the inductor "unimpeded". For DC, the resistance of the coil itself has a small blocking effect on the DC, which is ignored in the circuit analysis.
Resistance to AC: When AC passes through the inductive coil, the inductor will block the AC to a certain extent, and the inductive reactance of the inductive coil will block the AC.
