Question
Physics Question on Ray optics and optical instruments
The radius of curvature of the curved surface of a plano convex lens is 20 CM. if the refractive index of the material of the lens be 1.5, then the focal length of the lens will be :
A
20 cm
B
-20 cm
C
40 cm
D
40 cm
Answer
40 cm
Explanation
Solution
The correct answer is (D): 40 cm