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Electromagnetic Waves

Faraday’s Law in a Plane Wave

Description

Faraday’s law can be used to link the electric and magnetic fields in a plane electromagnetic wave. Here, the wavefront moves in the x-direction at a constant speed. The goal is to show how the field strengths must be related for the wave to stay consistent with Faraday’s law.

To apply the law, a...

Transcript

通过将法拉第定律应用于沿 +x 方向以恒定速度传播的平面波前,可得到电场与磁场之间的关系。

考虑一个高度为 "a"、面积矢量沿 +z 方向的矩形。

沿矩形逆时针方向积分时,电场在长度"PQ"上为零,或垂直于各边元,仅在长度"RS"上有贡献,使积分结果为非零值。

为了满足法拉第定律,必须存在一个沿 +z 方向的磁场分量,该分量可为矩形区域提供非零的磁通量,从而产生非零的磁通量时间导数。

在时间 "dt" 内,波传播的距离为 "c dt"。在传播过程中,它扫过的面积等于 "ac dt<...

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