A thin lens made of a material of refractive index
Question:

A thin lens made of a material of refractive index $\mu 2$ has a medium of refractive index $\mu 1$ on one side and a medium of refractive index $\mu 2$ on the other side. The lens is biconvex and the two radii of curvature have equal magnitude R. A beam of light travelling parallel to the principal axis is incident on the lens. Where will the image be formed if the beam is incident from (a) the medium $\mu 1$ (b) from the medium $\mu s$ ?

Solution: