Many objects around you contain electromagnets. They are found in electric motors and loudspeakers. Electric bells like the ones used in most schools also contain an electromagnet. The slideshow ...
diagrams, and live-action demonstrations. The film introduces viewers to the workings of electromagnets, generators, and transformers, with disembodied hands conducting experiments to illustrate ...
一些您可能无法访问的结果已被隐去。
显示无法访问的结果