静电场中电场强度和电位关系式应用探讨

The Discussion of Application of the Relationship Equation between Electric Intensity and Electric Potential in Static Field

在静电场中,对电位函数求负梯度可以得到电场强度矢量。但在现行的教材中没有提到该关系式的适用条件,使学生对其有错误的理解。本文通过采用电场强度积分表达式和对电位求负梯度来求解电场强度的两道例题,分析了公式E=-Φ产生错误应用的原因,由此强调该公式的应用条件,以供教学参考。

The minus gradient of electric potential can obtain electric intensity in static field. The application con- dition of the relationship equation is usually ignored in present teaching materials, which makes students have wrong comprehension about it. Two solutions are applied in two examples, which are the integral formula of electric intensity and the minus gradient of electric potential. The reasons for wrong application of the latter solution are an- alyzed. The application condition of minus gradient of electric potential is emphasized to be a teaching reference.