• 2022-05-27
    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点的磁感应强度大小等于[ ]。[img=98x70]18031eb892867fe.png[/img]
    A: [img=33x44]18031eb89b6a7cf.png[/img]
    B: [img=26x44]18031eb8a34611b.png[/img]
    C: 0
    D: [img=95x51]18031eb8ab63d30.png[/img]
    E: [img=89x51]18031eb8b8024df.png[/img]
  • 举一反三