The exhibition item you see is called "Iron Particle Art", which vividly showcases the magnetic field and magnetic lines of a magnet. We can try pressing different music buttons, so that we can see the iron particles dancing rhythmically with different music playing. What is the reason for this? There is a matrix of electromagnets hidden beneath the stage, and the current inside the electromagnets is controlled by a program. When we press the button, the iron particles become small magnets in the magnetic field generated by the electromagnets, forming a pointed shape. The magnitude and direction of the current inside the electromagnetic coil will change with the music, and the generated magnetic field will also change accordingly. The iron particles will produce different motion states under the dynamic magnetic field, dancing to the rhythm of the music. Extension knowledge: Any magnet has a magnetic field, and the range that magnetic field lines can reach is the size of the magnetic field of that magnet. Due to the characteristic of repulsion between poles and attraction between poles, magnetic field lines starting from one pole will return to the other pole, forming a circular arc magnetic field. The magnetic strength of a magnet can be determined by the amount of iron powder. When the opposite poles of a magnet attract each other, circular magnetic lines will appear. When two magnets are opposite in polarity, the magnetic field lines will repel each other but not attract each other.https://zoomkingzg.com/