Wave optics practice · Mixed difficulty

${n^{th}}$ Bright fringe if red light $\left( {{\lambda _1} = 7500\mathop \mathrm{A}\limits^ \circ } \right)$ coincides with ${\left( {n + 1} \right)^{th}}$ bright fringe of green light $\left( {{\lambda _2} = 6000\mathop \mathrm{A}\limits^ \circ } \right)$. The value of $n = ?$

Colours in thin films are due to

A scientist is observing a bacteria through a compound microscope. For better analysis and to improve its resolving power he should. (Select the best option)

Assertion: Transverse wave nature of light is proved by polarisation

Reason: According to Maxwell, light is an electro-magnetic wave but not mechanical wave.

In YDSE if white light is used then.

Which of the following is a dichroic crystal?

Which of the following phenomenon exhibits particle’s nature of light?

Red light of wavelength $625\;nm$ is incident normally on an optical diffraction grating with $2 \times {10^5}\;lines/m$. Including central principal maxima, how many maxima may be observed on a screen which is for from the grating?

Assertion: In Young's double slit experiment, the fringe width for dark fringes is same as that for white fringes.

Reason: In Young's double slit experiment, when the fringes are performed with a source of white light, then only dark and bright fringes are observed.

In the light of the above statements, choose the most appropriate answer from the options given below.

A rocket is going towards moon with a speed $v$. The astronaut in the rocket sends signals of frequency $v$ towards the moon and receives them back on reflection from the moon. What will be the frequency of the signal received by the astronaut (Take $v \ll c$ )

Unpolarised light is incident on a dielectric of refractive index $\sqrt{3}$. What is the angle of incidence if the reflected beam is completely polarised?

Fraunhoffer lines are obtained in

Diffraction pattern of a single slit consists of a central bright band which is

${S_1}\;and\;{S_2}$ are two coherent sources. The intensity of both sources are same. If the intensity at the point of maxima is $\mathrm{4}\;\mathrm{W}{\mathrm{m}^{ - 2}}$, the intensity of each source is

Critical angle for certain medium is ${\sin ^{ - 1}}\left( {0.6} \right).$ The polarizing angle of that medium is

A single slit is used to observe diffraction pattern with red light. On replacing the red light with violet light the diffraction pattern would

The central fringe of the interference pattern produced by light of wavelength $6000 \mathop {\text{A}}\limits^{\text{o}}$ is found to shift to the position of 4th bright fringe after a glass plate of refractive index 1.5 is introduced in front of one of slits in Young's experiment. The thickness of the glass plate will be

Light of wavelength $6000 ~\mathop {\text{A}}\limits^ \circ$ is incident normally on a single slit of width $24 \times 10^{-5} \mathrm{~cm}$. Find out the angular position of second minimum from central maxima?

Statement I : In Young's double slit experiment, the number of fringes observed in the field of view is small with longer wavelength of light and is large with shorter wavelength of light.

Statement II : In the double slit experiment the fringe width depends directly on the wavelength of light.

At two points $P\;and\;Q$ on screen in Young's double slit experiment. Waves from slits
${S_1}\;and\;{S_2}$ have a path difference of $0\;\mathrm{and}\;\frac{\lambda }{4}\mathrm{.}$ respectively. The ratio of intensities at
$P\;and\;Q$ will be

To increase the resolving power of a telescope

The main difference between the phenomena of interference and diffraction is that

A two-slit Young's interference experiment is done with monochromatic light of wavelength $6000{\mkern 1mu} \;\mathop {\text{A}}\limits^ \circ$. Those slits are $2 \,{~mm}$ apart. The fingers are observed on a screen placed $10\, {~cm}$ away from the slits. A transparent plate of thickness of $0.5 \,{~mm}$ is placed in front of one of the slits. It is found that the interference pattern shifts by $5 \,{~mm}$. What is the refractive index of the transparent plate?

Statement-1: Two thirds of possible values for phase difference result in constructive interference and one third results in destructive interference.
Statement-2: Interference is called constructive if the amplitude of the superposed waves exceeds that of one individual wave.

Plane wave front is incident on a single slit of width $0.2 \mathrm{~mm}$ by which Fraunhoffer diffraction pattern is formed by lens of focal length $1 \mathrm{~m}$. If the second minima is formed at a distance of $3 \mathrm{~mm}$ from the centre then find the wavelength of light.

In YDSE setup, light of wavelength $640 \mathrm{~nm}$ is used with $d=0.8 \mathrm{~mm}$ and $D=1 \mathrm{~m}$. If intensity at central maxima is $I_0$ and it's position is $y=0$

Assertion : Light ray passing through water droplet is partially polarized.
Reason : Water is a polar molecule.

Which of the following statements is true, when spherical waves fall on a plane refracting surface, separating two media

Which of the following can be used to control the intensity, in sunglasses, window-panes, etc.?

The equation of two light waves are

$\begin{aligned} & y_1=A_1 \sin 2 \omega t \\ & y_2=A_2 \cos \left(2 \omega t+\frac{\pi}{6}\right) \end{aligned}$

What will be the value of phase difference at time $t$