题目1单选题
一无限大不导电的薄片在一侧带有面电荷密度 <img src="http://p.ananas.chaoxing.com/star3/origin/e8db7de5cd42bcf829dc83237477f02a.gif">,电势差为50V的两等势面应相距多远?()A. <img src="http://p.ananas.chaoxing.com/star3/origin/af68fede8e93d17bac59514b1745f7aa.gif">B. <img src="http://p.ananas.chaoxing.com/star3/origin/b76c3052001f0d44a745b9cd8bc75ea2.gif">C. <img src="http://p.ananas.chaoxing.com/star3/origin/20c444bffcd35f4c0989593fcdd2e2d6.gif">D. <img src="http://p.ananas.chaoxing.com/star3/origin/1d6da9e9abef1659cfccec50f6b48fa0.gif">