Embibe Experts Solutions for Chapter: Ray Optics, Exercise 1: BITSAT 2017

A convex lens of focal length $25 \mathrm{cm}$ produces images of the same magnification $2$, when an object is kept at two positions $x_1$ and $x_2$ $\left(x_1>x_2\right)$ from the lens. The ratio of $x_2$ and $x_1$ is

In the shown situation, if middle portion of the lens is painted black, then

A convex lens shown in the figure is made up of two types of transparent materials. A point sources of light is placed on its principal axis. If reflections from the boundaries between layers are ignored, the lens will form

A planoconvex lens has thickness of $4 \mathrm{cm}.$ When placed on a horizontal table, with the curved surface in contact with it, the apparent depth of the bottom most point of the lens is found to be $3 \mathrm{cm}.$ If the lens is inverted such that the plane face is in contact with the table, the apparent depth of the centre of the plane face is found to be $\frac{25}{8} \mathrm{cm}.$ The focal length of the lens is (assume thickness of lens to be negligible)

The focal length of a thin convex lens for red and blue rays are $100 \mathrm{cm}$ and $96.8 \mathrm{cm}$ respectively. Then, the dispersive power of the material of the lens is

A plano-convex lens fits exactly into a plano-concave lens. Their plane surfaces are parallel to each other. If lenses are made of different materials of refractive indices ${\mu }_1$ and ${\mu }_2,R$ is the radius of curvature of the curved surface of the lenses, then the focal length of combination is