Embibe Experts Solutions for Chapter: Wave Optics, Exercise 7: Exercise (Previous Year Questions)

A parallel beam of fast moving electrons is incident normally on a narrow slit. A fluorescent screen is placed at a large distance from the slit. If the speed of the electrons is increased, then which of the following statements is correct?

In a double slit experiment, the two slits are $1 \mathrm{mm}$ apart and the screen is placed $1 \mathrm{m}$ away. A monochromatic light of wavelength $500 \mathrm{nm}$ is used. What will be the width of each slit for obtaining ten maxima of double slit within the central maxima of single slit pattern? 

For a parallel beam of monochromatic light of wavelength $\lambda$ diffraction is produced by a single slit whose width $a$ is of the order of the wavelength of the light. If $D$ is the distance of the screen from the slit, the width of the central maxima will be 

The intensity at the maximum in a Young’s double- slit experiment is $I_0$. Distance between two slits is $d=5\lambda$, where $\lambda$ is the wavelength of light used in the experiment. What will be the intensity in front of one of the slits on the screen placed at a distance $D=10 \mathrm{d}$?

The ratio of resolving powers of an optical microscope for two wavelengths ${\lambda }_1=4000 \mathrm{\AA }$ and ${\lambda }_2=6000 \mathrm{\AA }$ is 

Two Polaroids $P_1$ and $P_2$ are placed with their axis perpendicular to each other. Unpolarised light with intensity $I_0$ is incident on $P_1$. A third polaroid $P_3$ is kept in between $P_1$ and $P_2$ such that its axis makes an angle ${45}^o$ with that of $P_1$. The intensity of transmitted light through $P_2$ is

In YDSE, the intensity of central bright fringe is $8 \mathrm{mW} {\mathrm{m}}^{-2}$. What will be the intensity at $\lambda /6$ path difference?

In Young's double slit experiment the separation $d$ between the slits is $2 \mathrm{mm},$ the wavelength $\lambda$ of the light used is$5896 \mathrm{\AA }$ and distance $D$ between the screen and slits is $100 \mathrm{cm}.$ It is found that the angular width of the fringes is $0.20^{\circ} .$ To increase the fringe angular width to $0.21^{\circ}$ (with same $\lambda$ and $D$ ) the separation between the slits needs to be changed to