Question

On what factors the focal length of the lens depend?

Answer 1

\(\frac{1}{f}=(n-1)\left(\frac{1}{R_{1}}-\frac{1}{R_{2}}\right)\)

So, f depends on following factors:

1. Radius of curvature of lens.

2. Refractive index of lens material.

3. Refractive index of medium in which lens is placed.