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प्रश्न
State two differences between an electromagnet and a permanent magnet.
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उत्तर
| Electromagnet | Permanent magnet | |
| i. | It is made up of soft iron. | It is made up of steel. |
| ii. | The magnetic field strength can be changed. | The magnetic field strength cannot be changed. |
| iii. | Electromagnets of very strong field can be made. | Permanent magnets are not so strong. |
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