Difference Between Electromagnet and Permanent Magnet or Bar Magnet
Main difference between an electromagnet and permanent magnet is that the former can have a magnetic field when electric current flows through it and disappears when the flow of the current stops.
Bar magnet | Electromagnet |
(1) The bar magnet is a permanent magnet. | An electromagnet is a temporary magnet. Its magnetism is only for the duration for which current passes through it, so the magnetism of an electromagnet can be switched on or switched off as desired. |
(2 ) A permanent magnet produces a comparatively weak force of attraction. | An electromagnet can produce very strong magnetic force. |
(3)The strength of a permanent magnet cannot be changed. | The strength of an electromagnet can be changed by changing the number of turns in its coil or by changing the current passing through it. |
(4)The (north-south) polarity of permanent magnet is fixed and cannot be changed. | The polarity of an electromagnet can be changed by changing the direction of current in its coil. |
(5)It is usually made of hard materials | It is usually made of soft materials |
(6)Once magnetic properties is lost, it becomes useless | Removal of magnetic properties is temporary |