CUET Preparation Today
CUET
Physics
Ray Optics
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 focal length of lens will be:
20 cm
-20 cm
-40 cm
40 cm
The correct answer is Option (4) → 40 cm