静电场描绘实验中，通常是采用直流电场来模拟静电场（可模拟平行板电场，一对正负点电荷电场及单个点电荷电场）．如在导电纸上用一对平行金属条电极就可模拟平行板电场，理论上讲，平行板中央的等势线应该是相互平行的直线．但实验的结果往往是导电纸上各等电势点所连成的线? In the electrostatic field depiction experiment, a direct-current electric field is usually used to simulate an electrostatic field (a parallel-plate electric field, a pair of positive and negative point-charge electric fields, and a single point-charge electric field). For example, a pair of parallel metal strip electrodes can be used to simulate the parallel plate electric field on conductive paper. Theoretically, the equipotential lines in the center of parallel plates should be parallel to each other. But the result of the experiment is often the line connected to each potential point on the conductive paper?