17. The speed of light in a material is 0.50c. What is the critical angle of a light ray at the interface between the material and a vacuum?
(A) 21°
(B) 24°
(C) 27°
(D) 30°
(E) 33°
答案:登入後查看
統計: 尚無統計資料
統計: 尚無統計資料