Physics - Geometrical Optics Question with Solution | TestHub

The adjacent figure shows a thin plano-convex lens of refractive index ${\mu }_1$ and a thin plano-concave lens of refractive index ${\mu }_2$, both having same radius of curvature $R$ of their curved surfaces. The thin lens of refractive index ${\mu }_3$ has radius of curvature R of both its surfaces. This lens is so placed in between the plano-convex and plano-concave lenses that the plane surfaces are parallel to each other. The focal length of the combination is