The invention discloses a rotating ball device for teaching, and relates to the technical field of teaching aids. The device comprises a driving
assembly, the top of the driving
assembly is fixedly connected with a ball
assembly, and the surface of the ball assembly is bonded with an index line assembly through an
adhesive. Directional rotation of the sphere is achieved through the driving assembly, the spiral relation between the current direction and the magnetic induction line in the
ampere rule can be dynamically presented in combination with the spherical surface index line assembly and the internal
magnet structure, and when the electrified
copper rail generates annular current, an observer can observe the annular current through the center window of the transparent sphere. The law that the direction of a magnetic induction line of a sphere center changes along with current can be visually seen, the sphere rotates in cooperation with the sphere, three-dimensional spiral linkage of current-magnetic induction line is clearly shown, in
Lorentz force teaching, when an external
magnet is close to the surface of the sphere, spherical surface motion charge identification is in real-time linkage with the rotation direction of the sphere, and the teaching efficiency is improved. And the charge movement direction, the
magnetic field direction and the stress direction are dynamically associated in a
space vector form.