如图所示,平板电容器(忽略边缘效应)充电时,沿环路L1.L2磁感应强度<img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_6bf085d8-97f1-459b-a555-ea623dfda9bc.png" alt="_PhotoUploadUtils_6bf085d8-97f1-459b-a555-ea623dfda9bc.png">的环流中,若将图中L1.L2都反向,则有<img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_f75030df-178a-47bc-9d9f-009dc692c9a0.png" alt="_PhotoUploadUtils_f75030df-178a-47bc-9d9f-009dc692c9a0.png">.<img src="http://edu-image.nosdn.127.net/9CAE95D6986BBE2B5BC8E25D3FAC875F.png?imageView&amp;thumbnail=890x0&amp;quality=100" alt="9CAE95D6986BBE2B5BC8E25D3FAC875F.png?imageView&amp;thumbnail=890x0&amp;quality=100">