The energy of electric field stored in the capacitor placed in an alternating electromagnatic field is concluded by using the principle of superposition and by starting with Maxwellequations.
Based on the principle of superposition of plane waves, the same expressions are derived as those based on Maxwell 'e fieldequations.
从平面波叠加原理出发，导出与从麦克斯韦方程组出发同样的表达式。
3
Electromagnetic Field and Electromagnetic Wave make students grasp the theorem and the physical meaning of the Maxwellequations and mathematical expressions.