Georg Simon Ohm, German physicist, c 1840

Georg Simon Ohm, German physicist, c 1840. Photogravure after a painting. George Simon Ohm (1789-1854) was Professor of Physics at Nuremburg and Munich Universities. He is famous for discovering the law governing the relationships between voltage resistance and electric currents. 'Ohm's Law' states that the relationship of current through most materials is directly proportional to the potential difference applied across the material (V=IR). His findings were published in 1827 in his seminal work on the theory of electricity, 'Diegalvanische Kette, mathematische bearbeitet'. The SI unit (International System of scientific units) of electrical resistivity, the Ohm, is named after him. From a collection of portraits of scientists published by Photographische Gesellschaft, Berlin, 1910. Dimensions: 460mm x 340mm. ©SSPL/Science Museum