Ohm's Law

Georg Simon Ohm

Ohm’s Law is the core equation used to study electrical circuits. It holds that the potential difference between two points on a circuit equals the product of the current between those two points and the total resistance of all electrical devices existing between those two points. The greater the voltage of a battery (or its total electrical potential difference), the greater its current will be. Likewise, with greater resistance, there will be less current.

Georg Simon Ohm was born in Erlangen, Germany, in 1787 and entered that city’s university in 1805, where he received a doctorate. He taught mathematics in local schools and performed experiments in physics in a school physics laboratory, trying to master the principles behind electromagnetism. He became professor of mathematics at the Jesuits’ College in Cologne in 1817.

In 1826, he published papers giving a mathematical model for the way the circuits conducted heat in Fourier’s studies. In May 1827, Ohm published Die galvanische Kette, mathematisch bearbeitet, which described the relationship between electromotive force, current, and resistance later known as Ohm's law. Ohm obtained the experimental data from which he first formulated his law on 8 January 1826. But his study received a muted reception upon its initial release, and he resigned his position at Cologne, eventually taking a new professorship in Nurenberg in 1833.

Ohm’s findings would catalyze new research into electricity in the coming decades. In 1841, Ohm was awarded the Royal Society’s highest award, the Copley Medal. The term 'Ohm' was adopted as the unit of electrical resistance in 1872.