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.
The conditions required to obtain permanent electromagnet when a current carrying solenoid is used are:
● The rod inside solenoid should be made of a magnetic material like steel, soft iron etc. This type of material can retain the magnetic properties for a long time after magnetization.
● Direct current should be used for solenoid.
● The turns should be closely packed and large in number for producing a uniform strong magnetic field
Fig. : A current carrying solenoid