During the negative cycle, how the inductor returns the power? The following is related to AC circuits:
When an inductor(or a capacitor) is connected to an AC source it consumes some power in the form of some field during first T/4 time interval and returns the consumed power during the next T/4 time interval. 
How is the consumed power returned to the source and in what form?
What happens to the main current in the circuit during the positive and negative half cycles?
I doubt that in case of capacitor, the consumed power, stored in the form of electric feild, is used to increase the current in the circuit,and thus returns the power consumed but I am not sure as if it occurs the main current will no longer be sinusoidal !!!
Also, I cannot think anything in the case of an inductor.
 A: First of all an ideal capacitor or inductor does not “consume” power like a resistor. They store energy. For a capacitor the energy is stored in its electric field and equals $\frac{CV^2}{2}$. For an inductor the energy is stored in its magnetic field and equals $\frac{LI^2}{2}$. 
These energies are returned to the circuit by capacitor discharge current (which reduces its voltage and therefore stored energy) and returned by the inductor when its current is ramped down and its magnetic field collapses, reducing the energy stored in its magnetic field.
Hope this helps.
A: 
How is the consumed power returned to the source and in what form? 

Bob D’s answer is the short story of what happens. Let us go more in detail.
A capacitor is something like a wall on the way that electrons travel from a source to a sink. The electrons accumulate on one side and push the electrons away from the over side. This happens as long as the full capacitance of the capacitor is not reached. When the source is switched off, the electrons remain trapped and the ideal capacitor remains charged.
As long as the capacitor is charged an electric field exists between the two plates. This field represents the amount of electrons the capacitor is filled with. This is a truism but said explicitly to see now what happens with the inductor.
An inductor is a device in which a magnetic field is induced by the flow of electrons. The main difference to a capacitor is that this process is dynamic; the magnetic field dissipates if the source is switched of.
How the electrons are involved in the induction of the magnetic field in inductors? In the wound wire of such an inductor, the electrons are moved by the source and forced into a circular (spiral) path by the coil. This acceleration aligns the electrons magnetic fields and creates a common field. This is expressed by the statement that accelerated charges induce a magnetic field.
The alignment of the charges magnetic fields within the coil increases the resistance of the coil. When the source is switched off, the electrons come to rest, the acceleration goes to zero, the direction of the magnetic fields of the electrons goes back to random distribution and the electrons are temporarily pushed in the opposite direction to the current.  This is expressed by the statement that decelerated charges induce an opposite current (Lenz’s law).
Having a LC circuit, the electrons are going from the capacitor to the inductor and back, in the capacitor the agglomeration of the charges induces an common electric field, in the inductor the alignment of the magnetic dipoles induce a common magnetic field.
