A spherical convex surface of radius of curvature R separates glass (refractive index 1.5) from air. Light from a point source placed in air at…

Refraction from rarer to denser medium: $\displaystyle \frac{n_{1}}{-u}+\frac{n_{2}}{v}=\frac{n_{2}-n_{1}}{R}$ $\displaystyle u=-\frac{R}{2}, n_{1}=1, n_{2}=1.5$ $\displaystyle \frac{2}{R}+\frac{1.5}{v}=\frac{1.5-1}{R}$ $\displaystyle \frac{1.5}{v}=\frac{0.5}{R}-\frac{2}{R}$ $\displaystyle \frac{1.5}{v}=-\frac{1.5}{R}$ $\displaystyle v=-R$ The image is virtual, in air, at distance R.