Wave Optics - Optics - Physics Previous Year Questions

Two identical light waves, propagating in the same direction, have a phase difference \(\delta\). After they superpose the intensity of the resulting wave will be proportional to

A plastic sheet (refractive index = 1 6. ) covers one slit of a double slit arrangement for the Young’s experiment. When the double slit is illuminated by monochromatic light (wavelength = 5867 \(\mathop A\limits^o\)), the centre of the screen appears dark rather than bright. The minimum thickness of the plastic sheet to be used for this to happen is

An unpolarised beam of intensity I\(_0\) is incident on a pair of nicols making an angle of 60\(^\circ\) with each other. The intensity of light emerging from the pair is

In Young's double slit experiment with sodium vapour lamp of wavelength 589 nm and slit 0.589 mm apart, the half angular width of the central maxima is

In Young's double slit experiment, the two slits are separated by 0.2 mm and they are 1 m from the screen. The wavelength of the light used is 500 nm. The distance between 6th maxima and 10th minima on the screen is closest to

In Young's double slit experiment, the fringe width is found to be 0.4 mm. If the whole apparatus is immersed in a liquid of refractive index \(\frac{4}{3}\) without changing geometrical arrangement, the new fringe width will be

In the young's double slit experiment the fringe width of the interference pattern is found to be \(3.2 \times 10^{-4} \mathrm{~m}\), when the light of wave length \(6400^{\circ} \mathrm{A}\) is used. What will be change in fringe width if the light is replaced with a light of wave length \(4800^{\circ} \mathrm{A}\)

A light having wavelength \(6400^{\circ} \mathrm{A}\) is incident normally on a slit of width \(2 \mathrm{~mm}\). Then the linear width of the central maximum on the screen kept \(2 \mathrm{~m}\) from the slit is :

In Young's double slit experiment, the intensity of light at a point on the screen where the path difference is \(\lambda\) is \(\mathrm{K}\) units (\(\lambda\) is the wavelength of light used). The percentage change in intensity at a point where the path difference is \(\frac{\lambda}{6}\) and the above point is

A slit of width \(10 \times 10^{-7} \mathrm{~m}\) is illuminated by light of wavelength \(500 \mathrm{~nm}\). Angular position of the first minimum is

In Young's double slit experiment, the ratio of intensities of light from one slit to the other is \(9: 1\). If Im is the maximum intensity, what is the resultant intensity when they interfere at phase difference \(\phi\) ?

In Young's double slit experiment the ratio of phase difference between light waves reaching the third bright fringe and third dark fringe is

A monochromatic light of wavelength \(800 \mathrm{~nm}\) is incident normally on a single slit of width \(0.020 \mathrm{~mm}\) to produce a diffraction pattern on a screen placed \(1 \mathrm{~m}\) away. Estimate the number of fringes obtained in Young's double slit experiment with slit separation \(0.20 \mathrm{~mm}\), which can be accommodated within the range of total angular spread of the central maximum due to single slit.

Two narrow parallel slits illuminated by a coherent monochromatic light produces an interference pattern on a screen placed at a distance \(\mathrm{D}\) from the slits. The separation between the dark lines of the interference pattern can be increased by

In Young's double slit experiment light of wavelength \(500 \mathrm{~nm}\) is used to form interference pattern. A uniform glass plate of refractive index 1.5 and thickness \(0.1 \mathrm{~mm}\) is introduced in the path of one of the interfering beams. The number of fringes that will shift due to this is

Incident light of wavelength \(\lambda=800 \mathrm{~nm}\) produces a diffraction pattern on a screen \(1.5 \mathrm{~m}\) away when it passes through a single slit of width \(0.5 \mathrm{~mm}\). The distance between the first dark fringes on either side of the central bright fringe is

The width of the fringes obtained in the Young's double slit experiment is \(2.6 \mathrm{~mm}\) when light of wave length \(6000^{\circ} \mathrm{A}\) is used. If the whole apparatus is immersed in a liquid of refractive index 1.3 the new fringe width will be :

When light wave passes from a medium of refractive index '\(\mu\)' to another medium of refractive index '\(2 \mu\)' the phase change occurs to the light is :

In the Young's double slit experiment \(n^{\text {th }}\) bright for red coincides with \((n+1)^{\text {th }}\) bright for violet. Then the value of '\(n\)' is: (given: wave length of red light \(=6300^{\circ} \mathrm{A}\) and wave length of violet \(=4200^{\circ} \mathrm{A}\)).

In a single slit diffraction experiment, for slit width '\(\alpha\)' the width of the central maxima is '\(\beta\)'. If we double the slit width then the corresponding width of the central maxima will be: