This exhibit features three permanent-magnet generators made of three kinds of magnetic materials with different magnetic properties such as neodymium ferro-baron, hycomax, and ferrite plate.

• 本展品展示用钕铁硼、铝镍钴、铁氧体三种不同磁性的材料做成的三个永磁发电机。用手柄同时转动他们，可以观察到发电量的不同。