Two similar thin equi convex lenses of focal length feach

Last updated: 6/3/2023

Two similar thin equi convex lenses of focal length feach are kept coaxially in contact with each other such that the focal length of the combination is F When the space between the two lenses is filled with glycerin which has the same refractive index p 1 5 as that of glass then the equivalent focal length is F2 The ratio F F will be 2 1 1 2 2 3 3 4 1 2 3 4