Georg Ohm gives his complete theory of electricity in a pamphlet published in Berlin in 1827, with the title Die galvanische Kette mathematisch bearbeitet, the most important of his works.
In this work, he states his law for electromotive force acting between the extremities of any part of a circuit is the product of the strength of the current, and the resistance of that part of the circuit .
This work, the germ of which had appeared during the two preceding years in the journals of Schweigger and Poggendorff, will exert an important influence on the development of the theory and applications of electric current.
Ohm's name has been incorporated in the terminology of electrical science in Ohm's Law, the proportionality of current and voltage in a resistor, and adopted as the SI unit of resistance, the ohm (symbol Ω).
Georg Simon Ohm was born into a Protestant family in Erlangen, Bavaria, (at that time a part of the Holy Roman Empire) son to Johann Wolfgang Ohm, a locksmith and Maria Elizabeth Beck, the daughter of a tailor in Erlangen.
Although his parents had not been formally educated, Ohm's father is a respected man who had educated himself to a high level and is able to give his sons an excellent education through his own teachings.
Of the seven children of the family only three survive to adulthood: Georg Simon, his younger brother Martin, who later becomes a well-known mathematician, and his sister Elizabeth Barbara.
His mother had died when he was ten.
From early childhood, Georg and Martin had been taught by their father, who had brought them to a high standard in mathematics, physics, chemistry and philosophy.
Georg Simon attended Erlangen Gymnasium from age eleven to fifteen where he had received little in the area of scientific training, which sharply contrasted with the inspired instruction that both Georg and Martin received from their father.
This characteristic made the Ohms bear a resemblance to the Bernoulli family, as noted by Karl Christian von Langsdorf, a professor at the University of Erlangen.
Georg Ohm's father, concerned that his son was wasting his educational opportunity, had sent Ohm to Switzerland, where, in September 1806, Ohm accepted a position as a mathematics teacher in a school in Gottstadt bei Nydau.
Professor Langsdorf had left the University of Erlangen in early 1809 to take up a post in the University of Heidelberg and Ohm would have liked to have gone with him to Heidelberg to restart his mathematical studies.
Langsdorf, however, had advised Ohm to continue with his studies of mathematics on his own, advising Ohm to read the works of Euler, Laplace and Lacroix.
Reluctantly, Ohm had taken his advice but left his teaching post in Gottstadt bei Nydau in March 1809 to become a private tutor in Neuchâtel.
For two years, he had carried out his duties as a tutor while he followed Langsdorf's advice and continued his private study of mathematics; in April 1811, he returned to the University of Erlangen.
Ohm's own studies had prepared him for his doctorate, which he received from the University of Erlangen on October 25, 1811.
Immediately joining the faculty there as a lecturer in mathematics, he left after three semesters because of unpromising prospects.
He could not survive on his salary as a lecturer.
The Bavarian government offered him a post as a teacher of mathematics and physics at a poor quality school in Bamberg, which Ohm accepted in January 1813.
Unhappy with his job, Georg began writing an elementary textbook on geometry as a way to prove his abilities.
When Ohm's high school was closed down in February 1816, the Bavarian government had sent him to an overcrowded school in Bamberg to help out with the teaching of mathematics.
After his assignment in Bamberg, Ohm had sent his completed manuscript to King Frederick William III of Prussia.
Satisfied with Ohm's book, the King had on September 11, 1817 offered Ohm a position at the Jesuit Gymnasium of Cologne, which has a reputation for good science education; Ohm had been required to teach physics in addition to mathematics.
The physics laboratory was well-equipped, allowing Ohm to begin experiments in physics.
As the son of a locksmith, Ohm has some practical experience with mechanical devices.
His writings are numerous.
