Name Two Factors on Which the Focal Length of a Lens Depends

Answer: An optical system’s focal length is a measurement of how strongly it converges or diverges light. The focal length (f) of a spherical mirror is the distance between the pole and the principal focus.

The focal length of a lens depends on the following factor: 

The refractive index of the glass from which a lens is constructed, as well as the curvature of its two surfaces.