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Question
Distinguish between ‘paramagnetic’ and ‘ferromagnetic’ substances.
Solution
| Paramagnetic | Ferromagnetic |
| Substances which are weakly attracted by a magnet are called paramagnetic substances. | Substances which are strongly attracted by a magnet are called ferromagnetic substances. |
| Paramagnetic materials lose their magnetism on removal of the external field and hence cannot be used to make permanent magnets. | Ferromagnetic materials retain some magnetism on removal of external field and hence can be used to make permanent magnets. |
| The susceptibility is positive but small. | The susceptibility is positive but very high. |
| In the absence of electric field, the net dipole moment is zero. | In the absence of electric field, the net dipole moment is non-zero. |
| Aluminium, manganese, chromium and platinum are some examples of paramagnetic substances. | Iron, nickel, cobalt, gadolinium, dysprosium and their alloys are some examples of ferromagnetic substances. |
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