As mentioned above, for vacuum μ =1 . For other media, μ can be less than or greater than 1. If μ is less than 1, then the magnetic lines of force prefer to pass through the vacuum rather than thought he substance comprising the medium. In other words, the magnetic lines of force are repelled away form the substance. Such substances are said to be diamagnetic. On the other hand, if μ is greater than 1, then the magnetic lines of force have greater tendency to pass through the substance rather than thought he vacuum. In other words, the magnetic lines of force are attracted towards the substance. Such substance is called paramagnetic. If μ is very high (i.e. of the order of force is very) high and the substance is said to be ferromagnetic. Ferromagnetism is exhibited mainly by iron, cobalt, nickel and hair alloys. It is a property of greater interest in the subject of physics only. In Chemistry diamagnetic and paramagnetic substances in a magnetic field is shown diagrammatically in fig. below:

          (a) Magnetic lines of force passing through vacuum.
          (b) Magnetic lines of force pushed away by the diamagnetic substance.
          (c) Magnetic lines of force drawn in by the paramagnetic substance.

For more help in Diamagnetic, paramagnetic and ferromagnetic substances click the button below to submit your homework assignment