题目内容
如图,虚线框abcd内为一矩形匀强磁场区域,ab=2bc,a′b′c′d′是一正方形导线框,a′b′与ab平行.若将导线框匀速地拉离磁场区域,以W1表示沿平行于ab方向拉出过程中外力所做的功,W2表示以同样速率沿平行于bc的方向拉出过程中所做的功,则W1=___________W2.![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241140373732242.jpg)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241140373732242.jpg)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114037388225.gif)
设bc=l,
则ab=2l,W1=F安·2l=BIl·2l=B
l·2l=
,
W2=F安′·l=BI′2l·l=B
·2l·l=
.
故W2=2W1,故W1=
W2.
则ab=2l,W1=F安·2l=BIl·2l=B
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114037404308.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114037404484.gif)
W2=F安′·l=BI′2l·l=B
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114037482437.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114037513482.gif)
故W2=2W1,故W1=
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114037388225.gif)
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目