An object is located on a wall, its image of equal size is to be obtained on a parallel wall with the help of a convex lens. The lens is placed at a distance '$$\mathrm{d}$$' in front of the second wall. The required focal length of the lens is
The critical angle for light going from medium '$$x$$' to medium '$$Y$$' is $$\theta$$. The speed of light in medium '$$x$$' is '$$V$$' . The speed of light in medium '$$Y$$' is
A biconvex lens $$\left(R_1=R_2=30 \mathrm{~cm}\right)$$ has focal length equal to the focal length of concave mirror. The radius of curvature of concave mirror is [Refractive index of material of lens $$=1.6$$ ]
The critical angle for light going from medium A into medium B is $$\theta$$. The speed of light in the medium A is $$\mathrm{V}_{\mathrm{A}}$$. What is the speed of light in the medium $$\mathrm{B}$$ ?