– The focal length of a bi-convex lens for which the radius of curvature of each surface is 20 cm and refractive index of the material of the lens is 1.5 is …..
A. 15 cm
B. 20 cm
C. 10 cm
D. 25 cm
Answer:B
– The focal length of a bi-convex lens for which the radius of curvature of each surface is 20 cm and refractive index of the material of the lens is 1.5 is …..
A. 15 cm B. 20 cm C. 10 cm D. 25 cm