Asnetcomp Tutorials: Energy stored in a capacitor and inductor

Electric energy is stored in a capacitor (in an electrostatic field) and in an inductor (in an electromagnetic field).

1) Energy stored in a capacitor

We explained this in the article "What a capacitor really is?" as below:

This can be explained without using work, which is more direct.

Capacitor function, or the relation of Capacitance, Current (changing) and Voltage (changing)

$i(t)= \frac{\mathrm{d}q(t)}{\mathrm{d}t}=C\frac{\mathrm{d}v(t)}{\mathrm{d}t}$

Integrate the both sides with respect to time

(q/time) x time = C v

q = Cv =C x Joule (Energy)/q

Integrate both sides with respect of q (which changes with time)

(1/2)q x q = C x Joule (Energy)

Then,

Joule (Energy) = (1/2)q x q x 1/C, which is again

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We want to add one more explanation in a similar but more general way so that it easily leads to a analogous explanation of Energy stored in an inductor

Basic function of a capacitor is as above used

$i(t)= \frac{\mathrm{d}q(t)}{\mathrm{d}t}=C\frac{\mathrm{d}v(t)}{\mathrm{d}t}$

Integrate the both sides with respect to time

(q/time) x time = C v

q = Cv =C x Joule (Energy)/q

The unit of q is Ampere x second.

Integrate the both sides with respect to voltage (0 to final V).

Ampere x second x voltage =