Wave optics practice · Mixed difficulty

A thin transparent film with refractive index 1.4, is held on circular ring of radius 1.8 cm. The fluid in the film evaporates such that transmission through the film at wavelength 560 nm goes to a minimum every 12 seconds. Assuming that the film is flat on its two sides, the rate of evaporation is _____ $\pi \times 10^{-13} \mathrm{~m}^3 / \mathrm{s}.$

If the free space between the plates is replaced by a transparent liquid of refractive index $1.5$ and the wavelength of light remains $4200 \mathop A\limits^ \circ$ the number of fringes seen will be:

Statement-1 : When light is incident from air to water then Brewster's angle is $\theta_{{B}}$ then if light is incident from water to air then Brewster's angle is $\frac{\pi}{2}-\theta_{{B}}$.
Statement-2 : When light goes from air to any medium of refractive index is then Brewster's angle $\left(\theta_{{B}}\right)$ is given by $\theta_{{B}}=\tan ^{-1}(\mu)$.

Monochromatic light of wavelength $600 \mathrm{~nm}$ is incident from air on a glass surface (refractive index of glass is $1.5$). The frequency of the refracted light will be

For the constructive interference the path difference between the two interfering waves must be equal to

Assertion: Diffraction is common in sound but not common in light waves.

Reason: Wavelength of light is more than the wavelength of sound.

Fraunhoffer spectrum is

Diameter of human eye lens is $2 {~mm}$. What will be the minimum distance between two points to resolve them, which are situated at a distance of $50 {~m}$ from eye. The wavelength of light is $5000\mathop {\text{A}}\limits^ \circ$

Intensity of light depends upon

If the intensities of the two interfering beams in Young’s double alit experiment be ${I_1}$ and ${I_2}$, then the contrast between the maximum and minimum intensity is good when

Two glass plates are touching at one end and separated by a thin wire at the other end. When a monochromatic parallel beam of wavelength $4200 \mathop A\limits^ \circ$ incident normally on the glass plates is reflected, an interference pattern of 30 fringes are observed. If the wavelength of light used is taken $7000 \mathop A\limits^ \circ$ instead of $4200 \mathop A\limits^ \circ$, the number of fringes observed will be:

A thin air film is formed by putting the convex surface of a plane-convex lens over a plane glass plate. With monochromatic light, this film gives an interference pattern due to light reflected from the top (convex) surface and the bottom (glass plate) surface of the film.

Statement I : When light reflects from the air-glass plate interface, the reflected wave suffers a phase change of $\pi$.

Statement II : The centre of the interference pattern is dark.

Light of wavelength 550 nm falls normally on a slit of width $22.0 \times {10^{ - 5}}cm$. The angular position of the second minima from the central maximum will be (in radians)

Fraunhoffer lines are obtained in

In an interference experiment, the spacing between successive maxima or minima is

The idea of secondary wavelets for the propagation of a wave was first given by

Two straight narrow slits separated by a distance 0.08m mare illuminated by a source of light of wavelength $5460\,\mathop \mathrm{A}\limits^ \circ$. If the fringes are measured with a micrometer eyepiece it is found that 2 fringes occupy a distance of 10.92mm. The distance of the eye piece from the slits is

In Huygen’s wave theory, the locus of all points in the same state of vibration is called

In Young’s double slit experiment, the separation between the slit and the screen increases. The fringe width

Given below two statements: One is labelled as Assertion (A) and other is labelled as Reason (R).
Assertion (A): Non-polar materials do not have any permanent dipole moment.
Reason (R): When a non-polar material is placed in an electric field, the centre of the positive charge distribution of it’s individual atom or molecule coincides with the centre of the negative charge distribution.
In the light of above statements, choose the most appropriate answer from the options given below.

If white light is used in the Newton’s rings experiment, the colour observed in the reflected light is complementary to that observed in the transmitted light is complementary to that observed in the transmitted light through the same point. This is due to

Resolving power of a telescope increases when

When a compact disc is illuminated by small source of white light, coloured bands are observed. This is due to

According to corpuscular theory of light, the different colours of light are due to

The wave theory of light, in its original form, was first postulated by

In a young's double slit experiment light of wavelength $600 \mathrm{~nm}$ is used. $\mathrm{P}$ is the nearest point from the central maximum where intensity is $3 / 4^{\text {th }}$ of the maximum intensity. What percentage of the maximum intensity is observed at point $P$ if light is replaced by the wavelength $400 \mathrm{~nm}$ ?

In YDSE of equal width slits, if intensity at the centre of screen is $I_0$, then intensity at a distance of $\beta / 4$ from the central maxima is ($\beta$ is the fringe width):

The Brewster angle for the glass-air interface is ${54.74^ \circ }$. If a ray of light going from air to glass strikes at an angle of incidence ${45^ \circ }$, then the angle of refraction is $\left[ {\tan \,{{54.74}^ \circ } = \sqrt 2 } \right]$

Statement I : For a given medium, the polarising angle is $60^{\circ}$. The critical angle for this medium is $35^{\circ}$.

Statement II : $\mu=\tan i_\rho$.

Frequencies of light incident on a system of scattering particles are in the ratio of 1:2. Then, the intensity of scattered light in a particular direction is