断电自感现象的演示对说明自感现象和解释日光灯工作原理都很重要,并能给学生留下深刻的印象。可是这个看来简单的演示实验往往做不成功。我们认为要使这个演示成功,需要:一、铁芯线圈的电阻应明显小于灯泡的电阻;二,电源应能保证电键未断开时通过线 The demonstration of the self-inductance phenomenon of power failure is very important for explaining the self-induction phenomenon and explaining the working principle of the fluorescent lamp, and can leave a deep impression on the students. However, this seemingly simple demonstration experiment often fails. We believe that to make this demonstration successful, it is necessary to: First, the resistance of the core coil should be significantly less than the resistance of the bulb; Second, the power supply should be able to ensure that the key is not disconnected when passing through the line