Question
Question: A thin plano-convex lens acts like a concave mirror of focal length 0.2m, when silvered on its plane...
A thin plano-convex lens acts like a concave mirror of focal length 0.2m, when silvered on its plane surface. The refractive index of the material of lens is 1.5. The radius of curvature of the convex surface of the lens will be –
A
0.1 m
B
0.2 m
C
0.4 m
D
0.8m
Answer
0.2 m
Explanation
Solution
F = – 0.2 m
m = 1.5
F = 
\ – 0.2 = 
\ 0.2 = 
\ R = 0.2 m