## Energy

The
energy W consumed over time t due to power P dissipated in a resistance R
carrying a current I with a voltage drop V is:

W = Pt = V^{2}t / R = VIt = I^{2}tR

Similarly,
the energy W consumed over time t due to power P dissipated in a conductance
G carrying a current I with a voltage drop V is:

W = Pt = V^{2}tG = VIt = I^{2}t / G

The energy W
stored in a capacitance C holding voltage V with charge Q is:

W = CV^{2} / 2 = QV / 2 = Q^{2} / 2C

The energy W stored in an inductance L carrying
current I with magnetic linkage
Y is:

W = LI^{2} / 2 =
YI / 2 =
Y^{2} / 2L