Hans Christian Oersted discovered in 1820 that if you pass an electrical current though a wire it would create a magnetic field.
N'afọ 1820, ọkà mmụta sayensị Danish bụ Hans Christian Orsted chọpụtara na ọ bụrụ na ị tinye agịga kompas magnetized n'akụkụ waya na-ebu ugbu a, ọ na-akwagharị wee bụrụ ihe na-adịghị mma.