How does an inductor work?

Answer 1

Basically, an inductor is a coil of wire. The core of the inductor, the material it is would around, could be air, ferromagnetic material, or something else. The windings of the coil are usually copper wire, and they are coated with some kind of insulator, often enamel. It has two terminals, one at each end of the coil. Let's hook it up and see what happens.
When we apply a voltage to the coil, current will want to move through the windings. But the instant that current wants to start moving, that current will want to form a magnetic field around its path of travel. This is a fundamental concept as regards moving charges; they always form a magnetic field around their path of travel.
As the magnetic field begins to form, it will start to expand around the wire. As the field expands around one wire, that field will expand "across" other windings. Each winding will have an expanding magnetic field that "sweeps" or expands across all the other windings. As the expanding magnetic field around each wire sweeps all the other windings, it induces a voltage in those windings that opposes the voltage applied to the coil. The action of the opposing magnetic field wants to stop or prevent current flow. This is at the heart of how an inductor works, and this is the principle of induction in action. Let's follow through and tighten things up.
As the field expands and generates (induces) that opposite voltage, the inductive action will limit the ability of the windings to conduct current flow. Eventually the current will flow, but only after a bit of time. There is a "delay" between the application of voltage to an inductor and that inductor's ability to pass current through itself. This is why we say that current lags voltagein an inductor. The current only flows "later" after the voltage rises and peaks. The delay spoken of here is only very brief, but when we apply AC to an inductor (pure inductance), the current will lag the applied voltage by 90 degrees.
When voltage across an inductor peaks and falls off, the magnetic field that had built up will collapse. As this field collapses, it will again be sweeping all the windings in the coil, and will induce a voltage that wants to keep current flowing the way it was flowing already. The inductor is "resisting" a change in the current flow through it. And this is a fundamental characteristic of an inductor.
And inductor is a device that resists a change in current flow throught it. And current flow through an inductor will lag the applied voltage by 90 degrees in AC circuits, provided there is no resistance in the circuit. This is boilerplate electronics, and the electronics student will see this information in some form on a test.

Answer 2

the inductor acts as a short cicuit,we know that the reactance offered by a inductor is (i*2*pi*f*l)

where "l" is the inductance value......and the frequency of the dc current is zero.

hence it acts as short circuit