Jadhav, Ghanshyam Harishchandra
Mechanics / Electrodynamics
June 30, 2013
On 21 April 1820, during a lecture, Ørsted noticed to his surprise that a compass needle was deflected when an electric current from a battery was switched on and off. That finding leaded to a conclusion that the current carrying wire must be producing a magnetic field which must be applying a magnetic force on the magnetic needle. In perception of that one can easily guess that if a current in a wire exerts a magnetic force on a compass needle, then two such wires also should interact magnetically. This was guessed by Andre Marie Ampere and confirmed experimentally too. These findings leaded to the rapid development of the classical electrodynamics. In the rapid development one question left to be answered yet is that why a current carrying wire is producing a magnetic field. If the nature of the magnetic field, what we suppose today, is the real nature then why magnetic monopoles are absent in the universe. Suppose one could have found the interaction between two current carrying wires before Ørsted’s finding then what he could have guessed about the cause of interaction. At first he might have guessed the cause of interaction as an electric force and might have tried to solve the problem. Today’s picture of electricity might be different. The Ørsted’s finding forced people to think about the magnetic force as the cause of the interaction.