Discovered magnetic effect produced by electric current.
He completed hid studies at the University of Copenhagen with a thesis on Kant's philosophy and became chemical assistant to the medical faculty in 1799. In 1806 he was appointed Professor of Physics at Copenhagen. He founded the Danish Society for the Promotion of Scientific Knowledge. In 1829 he became the director of the Polytechnic Institute in Copenhagen.
Oersted's discovery of electromagnetism was made during a lecture in the spring of 1820. In 1822, after many fruitless attempts, he was the first to obtain a reasonable accurate value for the compressibility of water by using an ingenious piezometer and by ensuring that increased pressure was exerted both inside and outside the container. From his researches(1823) into thermoelectric junctions he concluded that such junctions produced a relatively high current at a relatively low potential difference compared with the voltaic cell.