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Question
Under what conditions permanent electromagnet is obtained if a current carrying solenoid is used? Support your answer with the help of a labelled circuit diagram.
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Solution
The following conditions are required to obtain permanent electromagnet when a current-carrying solenoid is used :
- Rod inside the solenoid should be made of a magnetic material like steel which should retain magnetic properties for a long time after magnetization.
- The current through the solenoid should be direct current.
- The number of turns in the solenoid should be large and closely packed so that a strong uniform magnetic field inside it is produced.
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