1) Hold the charged conductor with your right hand and let your thumb point to the current direction, then the direction of bending four fingers is the direction of the magnetic field around the straight line.

2)? right-hand screw rule

Hold the electrified coil in your right hand and let the four fingers bend to point to the current direction of the coil, then the direction pointed by your thumb is the direction of the magnetic field inside the coil.

It should be noted that if direct current flows into the conductor, the direction of the magnetic field around the conductor is fixed; If alternating current flows through a conductor, the magnitude and direction of the magnetic field will change with the change of current direction.

Luoyang mechanical and electrical school motor maintenance class, learn from you until you learn. The maintenance of power tools is also studied. Practice-oriented, one-on-one teaching by teachers.

(2)? Electromagnetic induction (right hand rule)

Open your right hand so that your thumb is perpendicular to the other four fingers and on the same plane, so that the magnetic field lines pass through your palm, with your thumb pointing in the direction of cutting the magnetic field lines and your four fingers pointing in the direction of induced electromotive force.

(3)? Influence of magnetic field on current (left-handed rule)

Open your left hand, make your thumb perpendicular to the other four fingers and on the same plane, let the magnetic field lines pass through your palm, and the four fingers point to the current direction. The direction of your thumb is the direction of the electromagnetic force on the electrified conductor.