With no current in it, there is no magnetic field and therefore zero energy, but as the current rises, the magnetic field grows, and the energy stored grows with it.
How do inductors store energy?
Like a capacitor, inductors store energy. But unlike capacitors that store energy as an electric field, inductors store their energy as a magnetic field. If we pass a current through an inductor we induce a magnetic field in the coil. The coil will store that energy until the current is turned off.
Thus, while the stored energy in a capacitor tries to maintain a constant voltage across its terminals, the stored energy in an inductor tries to maintain a constant current through its windings. Because of this, inductors oppose changes in current, and act precisely the opposite of capacitors, which oppose changes in voltage.
How do inductors work in DC circuits?
Now here is where inductors in DC circuits get really interestingIf we quickly open the switch and leave it as an open circuit after the inductor has been energized and the magnetic field has formed, the magnetic field collapses releasing the stored energy back into the inductor and the inductor becomes a voltage source for the circuit.
What happens if the current through an inductor is a constant?
When the current through an inductor is a constant, then the voltage across the inductor is zero, same as a short circuit. No abrupt change of the current through an inductor is possible except an infinite voltage across the inductor is applied. The inductor can be used to generate a high voltage, for example, used as an igniting element.
V(t) = V(−Rt/L)e V (t) = At t = ∞ t = ∞, V = 0 V = 0 so the inductor behaves as an short circuit. Because capacitors store energy in the form of an electric field, they tend to act like small secondary-cell batteries, being able to store and release electrical energy.
A fully "discharged" inductor (no current through it) initially acts as an open circuit (voltage drop with no current) when faced with the sudden application of voltage. After "charging" fully to the final level of current, it acts as a short circuit (current with no voltage drop).