Question
Question: For a spherical surface of radius of curvatures R, separating two media of refractive index m<sub>1<...
For a spherical surface of radius of curvatures R, separating two media of refractive index m1 and m2, the two principal focal lengths are f1 and f2 respectively. Which relation is correct –
A
f1 = f2
B
f2/m2 = f1/ m1
C
f2/m2 = –f1/ m1
D
–f2/m1 = f1/ m2
Answer
f2/m2 = –f1/ m1
Explanation
Solution
The surface has two principal focus given by
f1 = μ−1−R, f2 =
f2 = –mf1
Ž f2 = −μ1μ2 f1