Wave Optics Tes...

The Young's double slit experiment is done in a medium of refractive index $$4/3$$. A light of $$600\ nm$$ wavelength is falling on the slits having $$0.45\ mm$$ separation. The lower slit $$S_{2}$$ is covered by a thin glass sheet of thickness $$10.4\ \mu m$$ and refractive index $$1.5$$. The interference pattern is observed on a screen placed $$1.5\ m$$ from the slits as shown in figure.
Now, if $$600\ nm$$ light is replaced by white light of range $$400$$ to $$700\ nm$$, find the wavelengths of the light that from maxima exactly at point $$O$$.
[All wavelengths in this problem are for the given medium of refractive index $$4/3$$. Ignore dispersion.]

A whistle producing sound waves of frequencies 9500 Hz and above is approaching a stationary person with speed v $${ ms }^{ -1 }$$. the velocity of sound in air is 300 $${ ms }^{ -1 }$$. If the person hear frequencies up to a maximum of 10000 Hz, the maximum values of v up to which he can hear the  whistle is then

In a modified Young's double slit experiment, a monochromatic uniform and parallel beam of light of wavelength $$6000$$ and intensity $$(10/\pi)Wm^{2}$$ is incident normally on two circular apertures $$A$$ and $$B$$ of radii $$0.001\ m$$ and $$0.002\ m$$ respectively. A perfectly transparent film of thickness $$2000A^{\circ}$$ and refractive index $$1.5$$ for the wavelength of $$6000A^{\circ}$$ is placed in front of aperture $$A$$, as shown in the figure. Calculate the power (in watts) received at the focal spot $$F$$ of the lens. The lens is symmetrically placed with respect to the apertures. Assume the $$10\%$$ of the power received by each aperture goes in the original direction and is brought to the focal spot.

Consider a two slit interference arrangements such that the distance of the screen from the slits is half the distance between the slits. Obtain the value of D in terms of $$\lambda$$ such that the first minima on the screen falls at a distance D from the centre O.

In a YDSE with two identical slits, when the upper slit is covered with a thin, perfectly transparent sheet of mica, the intensity at the centre of screen reduces from its initial value. Second order minima is observed to be above this point and second order maxima below it. Which of the following can not be a possible value of phase difference caused by the mica sheet?

Initially interference is observed with the entire experimental set up inside a chamber filled with air, Now  the chamber is evacuated. With the same source of light used, a careful observer will find that.

A glass plate of refractive index, $$1.5$$ is coated with a thin layer of thickness t and refractive index $$1.8$$. Light of wavelength $$648$$ nm travelling in air is incident normally on the layer. It is partly reflected at upper and lower surfaces of the layer and the rays interfere constructively is?

In the adjacent, $$CP$$ represents a wavefront and $$AO$$ & $$BP$$, the corresponding two rays. Find the condition on $$\theta$$ for constructive interference at $$P$$ between the ray $$BP$$ and reflected ray $$OP$$.

In Youngs double slit experiment, the fringes are displaced by a distance $$x$$ when a glass plate of one refractive index $$1.5$$ is introduced in the path of one of the beams. When this plate in replaced by another plate of the same thickness, the shift of fringes is $$(3/2)x$$. The refractive index of the second plate is

In Youngs double slit experiment, the slits are $$2mm$$ apart and are illuminated with a mixture of two wavelengths $$\lambda=12000\ {A}^{o}$$ and $$\lambda=10000\ {A}^{o}$$. At what minimum distance from the common central bright fringe on a screen $$2m$$ from the slits will a bright fringe from one interference coincide with a bright fringe from the other?