electromagnetic field equations

例句：

1. 1.The equations describe the behavior of the electromagnetic field in a given region.
   这些方程描述了给定区域内电磁场的行为。
2. 2. The equationsare used to calculate the electric and magneticfields in a circuit.
   这些方程用于计算电路中的电场和磁场。
3. 3. The equationsare crucial for understanding the interactions between matterand energy in space-time.
   这些方程对于理解物质与能量在时空中相互作用至关重要。