field force line

基本解释

The invisible force field around the magnet becomes suddenly visible when the iron filings fall into line.
磁棒四周无形的力场在铁屑排列成行时，一下子展现出了它的真面目。
However, the speed of the rotor rotation speed did not change the high magnetic field, or magnetic line of force will not be able to cut the copper.
不过此转子转动速度没有磁场变换之速度高，否则磁力线将不能为铜棒所切割。
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Traveling-wave interaction and secondary magnetic field is generated electromagnetic force, which is a straight line to run the basic principles of electric motors.
行波磁场与次级相互作用便产生电磁推力，这就是直线电动机运行的基本原理。
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