Question

the radius of curvature of a lens is 30 cm then what is its focal length​

Answer 1

Answer::when radius of curvature , R = 30 cm then , R = 2f or f = R / 2 or

Explanation::  

Explanation:radius=30 cm focal length =radius/2 =30/2 =15 cm

Answer 2

Answer:

30+30=60

Explanation:

1. because the radius of curvature of a lens is half of the focal length. so it is said that 30+30=60