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.
Permanent electromagnet is obtained if
- direct current flows through the solenoid and
- steel rod (a magnetic substance) is placed inside the solenoid.
In other words, a steel rod can be made a permanent electro-magnet if it is placed inside a solenoid carrying direct current as shown in figure.