What are the rules of amperage?

Ampere rule, also called right-handed spiral rule, is a rule that expresses the relationship between the direction of magnetic induction line of current and the magnetic field excited by current. Ampere rule in electrified straight wire (Ampere rule 1): Hold the electrified straight wire with your right hand and let your thumb point to the direction of current, then the direction of four fingers is the direction around the magnetic induction wire; Ampere's Law in the Energized Solenoid (Ampere's Law 2): Hold the Energized Solenoid with the right hand so that the bending direction of the four fingers is consistent with the current direction, then the end pointed by the thumb is the N pole of the Energized Solenoid.

The above is the rigid standard statement in the textbook; There is a joke that the law of ampere is the same as that of women: don't call in when you enter, and don't call out when you leave. Help you understand.