Question

A double convex lens has two surfaces of equal radii R and refractive index n= 1.5 find its focal length​

Answer 1

Answer:

Answer is f = R

Step-by-step explanation:

Given, n = 1.5

R1 = R2 = R

Now,

1/f = (n-1) (1/R1 - 1/R2)

1/f = 1.5 -1 (2/R)

1/f = 5/10 × 2/R

1/f = 10/10R

1/f = 1/R

f = R

Hope it helps...