Embibe Experts Solutions for Chapter: Ray Optics, Exercise 2: Level 2

Yellow colour light is used as fog light because yellow colour,

A plane mirror is moving with velocity $4\hat{\mathrm{i}}+5\hat{\mathrm{j}}+8\hat{\mathrm{k}}$. A point object in front of the mirror moves with a velocity $3\hat{\mathrm{i}}+4\hat{\mathrm{j}}+5\hat{\mathrm{k}}$. Here $\hat{\mathrm{k}}$ is along the normal to the plane mirror and facing towards the object. The velocity of the image is:

The apparent depth of needle lying at the bottom of the tank which is filled with water to a height of $15.5 \mathrm{cm}$ is measured by a microscope to be $8.5 \mathrm{c}\mathrm{m}$. If water is replaced by a liquid of refractive index $1.94$ to the same height as earlier, then the displacement of the microscope needed to establish the focus on the needle again is $n \mathrm{\mu m}$. The value of $n$ is

A rectangular block is composed of three different glass prisms (with refractive indices ${\mu }_1,{\mu }_2$ and ${\mu }_3$) as shown in the figure below. A ray of light incident normal to the left face emerges normal to the right face. Then the refractive indices are related by-

On a bright sunny day, a diver of height $h$ stands at the bottom of a lake of depth $H$. Looking upward, he can see objects outside the lake in a circular region of radius $R$. Beyond this circle he sees the images of objects lying on the floor of the lake. If refractive index of waler is $\frac{4}{3},$ then the value of $R$ is :

The objective lens of a telescope has a diameter of $12.2 \mathrm{cm}$. The angular resolution of the telescope at the wavelength of $500 \mathrm{nm}$ is

The magnifying power of a telescope can be increased by

A ray of light incident on a glass sphere (refractive index $\sqrt{3}$) suffers total internal reflection before emerging but exactly parallel to the incident ray. The angle of incidence was