• 2022-05-27
    如图所示,无限长直导线在P处弯成半径为R的圆,当通以电流 I 时,则在圆心O点的磁感强度大小等于( )?[img=122x89]180329ea41320bf.bmp[/img]
    A: [img=33x44]180329ea498d67b.png[/img]
    B: [img=26x44]180329ea51d9071.png[/img]
    C: [img=83x44]180329ea59cee95.png[/img]
    D: 0
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