In 1820 , a Danish physicist Hans Christian Oersted observed that current flowing through a conducting
wire can produce a magnetic field around it and causes a magnetic needle to deflect.
After Oersted's discovery , study on magnetic effect of current w3as carried further French physicist during the same year , Francis Agro demostrated the current carrying conducter behaves like a magnet and can attract iron filings and can induce permanent magnetism in small magnetic needles. Thus it was concluded that every current carrying conducter is always surrounded by the magnetic field. This important discovery linked two important branches of physics-Electricity and Magnetism whcih till then considered as two distinct phenomena .
The brachof physics which deals with the magnetism caused due to electric current is called electromagnetism.