| Basis for Comparison | Electromagnet | Permanent Magnet |
|---|---|---|
| Generation of the magnetic field | Due to electric current | Due to material characteristics when magnetized. |
| Strength of magnetic field | The strength of the field depends on the total current flowing through the solenoid or coil. | Here the magnetic field strength solely relies on the respective material. |
| Magnetization | Temporary | Permanent |
| Type of material used | Generally the soft iron core | Usually, it makes use of hard material. |
| Demagnetization | It is demagnetized when the flow of current is stopped. | The material is demagnetized when it is subjected to extremely high temperatures. |
| The requirement of external power | Exist | Not Exist |
| Magnetic field retention | The field is retained till the time current flows through the material | These materials retain the field all the time. |
| Cost | Low | Comparatively high |
| Poles of the magnet | Can be varied. | Here the poles can never be changed. |
| Example | A solenoid across an iron | Bar Magnet |
| Applications | Electric bells, loudspeakers, motors, etc. | Cell phones, headphones, sensors, etc. |
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