Question

Relationship between focal
length and radius of curvature
is
O f = 2/1
O f = 2R
O f = r/3
O f = R/2​

Answer 1

Answer:

I think the answer is

Explanation:

f=2R

Answer 2

Answer:

F=R/2

is true only when the R is very much larger than the diameter of it's aperture