試題詳解

37. When a cube is inscribed in a sphere of radius r, the length L of a side of the cube is L = . If a positive point charge Q is placed at the center of the spherical surface, the ratio of the electric flux Qsphere at the spherical surface to the flux Qcbe at the surface of the cube is
(A)
(B)
(C) 1
(D)
(E)