1, Coulomb's law is the law of static point charge interaction;
2. Ampere's law is a rule that expresses the relationship between current and the direction of magnetic induction line of current excitation magnetic field;
3. Electromagnetic induction refers to the phenomenon of induced electromotive force due to the change of magnetic flux.
Data of three basic laws:
1, Coulomb's law was put forward by French physicist Coulomb in his paper "The Law of Electricity" in 1785. The interaction force between charges at two stationary points in vacuum is directly proportional to the product of their charges and inversely proportional to the square of their distance. The direction of the interaction force is on their connection line, charges with the same name repel each other, and charges with different names attract each other.
Coulomb's law is not only the basic law of electromagnetism, but also one of the basic laws of physics. Coulomb's law clarifies the law of interaction between charged bodies, determines the nature of electrostatic field, and lays the foundation for the whole electromagnetism.
2. Ampere rule is also called right-hand spiral rule. Ampere rule in electrified straight wire (Ampere rule 1): Hold the electrified straight wire with your right hand, let your thumb point in the direction of current, and then point your four fingers around the magnetic induction line;
The Ampere Rule (Ampere Rule 2) in the energized solenoid is to hold the energized solenoid with the right hand and let four fingers point to the current direction, then the end pointed by the thumb is the N pole of the energized solenoid. The right-hand spiral rule can be used to find the direction of the cross product of two vectors. For this purpose, whenever there is a cross product in physics, the right-handed spiral rule can be used.
3. The law of electromagnetic induction is also called Faraday's law of electromagnetic induction. The direction of electromotive force in the law of electromagnetic induction can be determined by Lenz's law or right-hand rule. The content of the right hand rule is to straighten the right hand so that the thumb is perpendicular to the four fingers, the palm faces the N pole of the magnetic field, the direction of the thumb is consistent with the direction of the conductor, and the direction pointed by the four fingers is the direction of the induced current in the conductor (the direction of the induced electromotive force is consistent with the direction of the induced current).
Lenz's law points out that the magnetic field of induced current should hinder the change of original magnetic flux. In short, as the magnetic flux increases, the generated current tends to decrease; However, when the magnetic flux becomes smaller, the generated current often makes it larger.