Embibe Experts Solutions for Chapter: Wave Optics, Exercise 3: Level 3

A wavefront is represented by the plane $y=3-x$. The propagation of wave takes place at

A parallel beam of light of all wavelength greater than $3000 \stackrel{0}{\mathrm{A}}$ falls on a double slit in a Young's double-slit experiment. It is observed that the wavelengths $3600 \stackrel{0}{\mathrm{A}}$ and $6000 \stackrel{0}{\mathrm{A}}$ are absent at a distance of $31.5 \mathrm{mm}$ from the position of the central maximum, and the orders of the interference at this point for the two wavelengths differ by $7 .$ If the distance between the slits and the screen is $1 \mathrm{m},$ the separation between the two slits (in $\mathrm{mm}$ ) is :

A thin oil film of refractive index $1.2$ floats on the surface of water $(\mu =\frac{4}{3}).$ When a light of wavelength $\lambda =9.6\times {10}^{-7}\mathrm{m}$ falls normally on the film from air, then it appears dark when seen normally. The minimum change in its thickness for which it will appear bright in normally reflected light by the same light is:

The path difference between two interfering waves at a point on the screen is $\frac{\lambda }{6}$. The ratio of intensity at this point and that at the central bright fringe will be (Assume that intensity due to each slit in same)

In Young's experiment for the interference of light, the separation between the slits is $d$ and the distance of the screen from the slits is $D$. If $D$ is increased by $0.5\%$ and $d$ is decreased by $0.3\%$ then for the light of a given wavelength, which one of the following is true?

"The fringe width......

Orange light of wavelength $6000\times {10}^{-10} \mathrm{m}$ illuminates a single slit of width $0.6\times {10}^{-4} \mathrm{m}.$ The maximum possible number of diffraction minima produced on both sides of the central maximum is ___________ .

If the wavelength of light used is $6000 \mathrm{\AA }.$ The angular resolution of the telescope of an objective lens having diameter $10 \mathrm{cm}$ is _____ $\mathrm{rad}$.

Two beams, $\mathrm{A}$ and $\mathrm{B}$, of plane polarized light with mutually perpendicular planes of polarization are seen through a polaroid. From the position when the beam $A$ has maximum intensity (and beam $B$ has zero intensity), a rotation of polaroid through $30°$ makes the two beams appear equally bright. If the initial intensities of the two beams are $I_{\mathrm{A}}$ and $I_{\mathrm{B}}$ respectively, then $\frac{I_{\mathrm{A}}}{I_{\mathrm{B}}}$ equals: