Question #42273

Diameter of a plano–convex lens is 6 cm. and its thickness at the centre is 3 mm. What is the focal length of the lens. If the speed of light in the material of lens is 2 × 108 m/s :-
(1) 30 cm
(2) 20 cm
(3) 10 cm
(4) 40 cm

Expert's answer

## Comments

## Leave a comment