<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/425b9040a8da4baeb90542a44b3249ca.jpeg?x-oss-process=image/sharpen,200"/>‎<br/> 两个正方形导体回路分别载有电流 <img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/668f7cc784e04f24bd954c91eeb6a9ea.png?x-oss-process=image/sharpen,200"/> 和<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/1ff893af2efb40f08d6beef9be55c42a.png?x-oss-process=image/sharpen,200"/>，电流方向如图所示。对于图示的闭合路径，<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/67b3ccd81cee4b0bacde8f3e84dab453.png?x-oss-process=image/sharpen,200"/>等于‎<b