Change of Polarities of an Electro-Magnet | Magnetism | Electrical Engineering
When a coil of insulated wire is placed around a magnetic substance and electric current is passed through the coil, the substance becomes an electro-magnet and produces flux. The magnetic substance is called 'magnetic core', the coil around it is called 'magnetising coil' and the current flowing through the coil is called 'exciting current'. The polarity developed at any end [...]