The
inductance of an electric circuit is one henry when an
electric current that is changing at one
ampere per
second results in an
electromotive force of one
volt across the inductor: V(t)= L \frac{\mathrm{d}I}{\mathrm{d}t}\,, where is the resulting voltage across the circuit, is the current through the circuit, and is the inductance of the circuit. The henry is a
derived unit based on four of the seven base units of the
International System of Units:
kilogram (kg),
metre (m),
second (s), and
ampere (A). Expressed in combinations of SI units, the henry is: \begin{alignat}{6} \mathrm{H} &= \dfrac{\mathrm{kg} {\cdot} \mathrm{m}^2}{\mathrm{s}^{2} {\cdot} \mathrm{A}^2} &&= \dfrac{\mathrm{N} {\cdot} \mathrm{m}}{\mathrm{A}^2} &&= \dfrac{\mathrm{J}}{\mathrm{A}^2} &&= \dfrac{\mathrm{kg} {\cdot} \mathrm{m}^2}{\mathrm{C}^2} &&= \dfrac{\mathrm{s}^2}{\mathrm{F}} \\ &= \dfrac{\mathrm{T} {\cdot} \mathrm{m}^2}{\mathrm{A}} &&= \dfrac{\mathrm{Wb}}{\mathrm{A}} &&= \dfrac{\mathrm{V} {\cdot} \mathrm{s}}{\mathrm{A}} &&= \dfrac{\Omega}{\mathrm{rad}{\cdot} \mathrm{Hz}} &&= \dfrac{\Omega{\cdot}\mathrm{s}} { \mathrm{rad}} &&= \Omega{\cdot}\mathrm{s} \end{alignat} where: , , , , , , , , , , , , , Hz =
hertz, rad =
radian (dimensionless quantity) ==Use==