Ohm (Ω)

The SI unit of electrical resistance, named for Georg Simon Ohm, whose 1827 work established the relationship between voltage, current and resistance.

Ohm's law states that current equals voltage divided by resistance, the single relationship from which almost all practical circuit design follows. Georg Simon Ohm published it in 1827 to a hostile reception: German academic opinion of the day held that physical law should be derived philosophically rather than measured experimentally, and he resigned his teaching post in the aftermath. Recognition came late, and the Royal Society awarded him the Copley Medal in 1841, a decade before his death.