When a thin plano-convex lens $(\mu =1.5)$ polished from its plane surface behave like a concave mirror of focal length $40 \mathrm{cm}$. The radius of curvature of the lens is

A thin convex lens of focal length $20 \mathrm{cm}$ is split into parts as shown in figure. An object $O$ is placed at distance $10 \mathrm{cm}$ from the lens. The distance between two virtual images of object will be

Consider the figure shown. What is the amount by which the horizontal ray incident on the prism is deviated after it is reflected from the vertical plane mirror?

A ray of light makes normal incidence on the diagonal face of a right-angled prism as shown in figure. If $\theta =$ $37°$ then the angle of deviation is $\left(\sin 37°=\frac{3}{5}\right)$

The refractive index of material of prism shown in figure is

Light is incident normally on the short face of a $30°-60°-90°$prism. A liquid is poured on the hypotenuse of the prism. If the refractive index of the prism is $\sqrt{3}$ , find the maximum refractive index of the liquid so that light is totally reflected