Henry (unit) Henry (unit) The henry (symbol: H) is the SI derived unit of electrical inductance. If a current of 1 ampere flowing through the coil produces flux linkage of 1 weber turn, the coil has a self inductance of 1 henry.‌ The unit 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 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
Ground loop (electricity) the cable If a current "I" from a separate source is flowing through the ground conductor, the resistance "R" of the conductor will create a voltage drop along the cable ground of "IR", so the destination end of the ground conductor will be at a different potential than the source end Since the differential amplifier has high impedance, little current flows in the signal wire, therefore there is no voltage drop across it: formula_15 The ground voltage appears to be in series with the signal voltage "V" and adds to it If "I" is an AC current this can result