Source: /cirosantilli/electrical-impedance

= Electrical impedance
{wiki}

<Ciro Santilli> distinctly remembers being taught that at basic <electrical engineering> school during <Ciro Santilli's undergrad studies at the University of São Paulo>.

It really allows you to do <alternating current> calculations much as you'd do DC calculations with resistors, quite poweful. It must have been all the rage in the 1950s.