The absolute refractive indices of glass and water are (frac{3}{2}) and (frac{4}{3}) respectively. The refractive index at the interface when a ray travels from water to glass is
-
A.
(frac{1}{2}) -
B.
(frac{8}{9}) -
C.
(frac{9}{8}) -
D.
(frac{17}{12}) -
E.
2
Correct Answer: Option C
Explanation
Ray travelling from water to glass;
(frac{text{speed of light in air}}{text{speed of light in glass}}) = (frac{3}{2})
= 3 x 108ms-1
X = 2 x 108ms-1
(frac{text{speed of light in air}}{text{speed of light in water}}) = (frac{4}{3})
= (frac{3 times 10^8}{g})
Y = 2.25 x 108ms-1
from water to glass;
Refractive = (frac{text{speed of light in water}}{text{speed of light in glass}})
= (frac{2.25 times 10^8}{2.00 times 10^8})
= 1.125
= (frac{9}{8})