1. Solenoid
What is an electromagnet? An electromagnet is a solenoid with an iron core.
What factors are related to the magnetism of an solenoid? Current and coil turns.
When the electromagnetic iron is energized, it can generate electromagnetism, and when it is powered off, the electromagnetism disappears; For example, when powered on, the electromagnet attracts the pin, while when powered off, the solenoid does not attract the pin.
Advantages of esolenoids:
1> The presence or absence of solenoid magnetism can be controlled by powering on or off;
2> The magnetic strength of the solenoid can be controlled by changing the magnitude of the current;
3> The polarity change of an solenoid can be controlled by changing the direction of the current.
