HENRY (UNIT)

The 'henry' (symbol: H) is the SI unit of inductance. It is named after Joseph Henry (1797-1878), the American scientist who discovered electromagnetic induction independently of and at about the same time as Michael Faraday (1791-1867) in England. The magnetic permeability of the vacuum is 4π×10⁻⁷ H/m (henry per metre).

Contents

Definition

SI multiples

See also

Definition

If the rate of change of current in a circuit is one ampere per second and the resulting electromotive force is one volt, then the inductance of the circuit is one henry.
:$H\; =\; dfrac\{mbox\{m\}^2\; cdot\; mbox\{kg\}\}\{mbox\{s\}^\{2\}\; cdot\; mbox\{A\}^2\}\; =\; dfrac\{mbox\{Wb\}\}\{mbox\{A\}\}\; =\; dfrac\{mbox\{V\}\; cdot\; mbox\{s\}\}\{mbox\{A\}\}\; =\; dfrac\{mbox\{m\}^2\; cdot\; mbox\{kg\}\}\{mbox\{C\}^2\}$

SI multiples

See also

★ Impedance

★ Inductor

★ Wb