The plane face of a planoconvex lens is silvered. The refractive index of material and radius of curvature of the curved surface of the lens are n…

The plane face of a planoconvex lens is silvered. The refractive index of material and radius of curvature of the curved surface of the lens are $\displaystyle \mathrm{n}$ and $\displaystyle \mathrm{R}$ respectively. This lens will behave as a concave mirror of focal length