問題詳情

8. A thin circular disk of radius R carries a total charge Q uniformly distributedon its surface. Assuming symmetric electric field on the two sides of the disk,which of the following expressions is a good approximation of the electric feldstrength at a distance r above the center of the disk, where r << R?
(A)


(B)


(C)


(D)


(E)

參考答案

答案：D
難度：計算中-1
書單：沒有書單，新增