On the point of an upright needle he laid horizontally a fine steel bar, which could turn to the right and left like the magnetic needle in a compass-box..
他在一根垂直的针头顶点，设置了一根水平的钢制细棍，它可以左右转动，就像罗盘里的磁针那样。
While the magnetic field surrounding a current-carrying wire is indeed interesting, it is quite weak for common amounts of current, able to deflect a compass needle and not much more.
当磁场围绕着带电导线时会有很有趣的现象发生，通常所用的电流产生的磁场相当的弱，最多可以使指南针的指针发生偏转。
While the magnetic field surrounding a current-carrying wire is indeed interesting, it is quite weak for common amounts of current, able to deflect a compass needle and not much more.
当磁场围绕着带电导线时会有很有趣的现象发生，通常所用的电流产生的磁场相当的弱，最多可以使指南针的指针发生偏转。
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