If the refractive index of glass is 1.5, what is the critical angle at the air-glass interface?
-
A.
sin-1(frac{1}{2}) -
B.
sin-1(frac{2}{3}) -
C.
sin-1(frac{3}{4}) -
D.
sin-1(frac{8}{9})
Correct Answer: Option B
Explanation
sin ic (frac{1}{n}) = (frac{1}{1 – 5})
i = sin-1(frac{1}{1 – 5})
= sin-1(frac{10}{15})
= sin-1(frac{2}{3})