Recent questions and answers in Wave Optics

In a Young's Double Slit experiment, the width of one of the two slits is double the other. If the amplitude of light coming from a slit is proportional to the width, find the ratio of the maximum to minimum intensity in the interference pattern.

answered Apr 19, 2014 by balaji.thirumalai

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Two monochromatic coherent sources of wavelength 5000 A are placed along line normal to screen as shown. Find the order of central bright fringe if $d = 0.5mm$ and $D = 1m$

answered Apr 19, 2014 by balaji.thirumalai

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In YDSE intensity at a point is $\bigg (\large\frac{1}{4} \bigg) $ of maximum intensity. Angular position of this point is :

answered Feb 20, 2014 by meena.p

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In YDSE if the source consists of two wave lengths $\lambda_1=4000 \;a^{\circ}$ and $\lambda _2 =4002\;A^{\circ}$ . Find the distance from centre where fringes disappear if $d= 1\;cm; D=1\;m$

answered Feb 20, 2014 by meena.p

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Two monochromatic coherent sources of wavelength 5000 A are placed along line normal to screen as shown. Then the condition for maxima at the point P is :

answered Feb 20, 2014 by meena.p

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In the ideal YDSE when a glass plate (RI= 1.5) of thickness t is introduced in path of one of interfering beams , the intensity at the position where central maximum occurred previously remains unchanged. The minimum thickness of glass plate is :

answered Feb 20, 2014 by meena.p

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In the YDSE apparatus shown the ratio of maximum to minimum intensity on screen is 9. The wavelength of light used is $\lambda$, the value of y is :

answered Feb 19, 2014 by meena.p

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In YDSE $\large\frac{d}{D}$$=10^4$ (d= distance between slits ; D= distance of screen from slits). at a point P on screen resulting intensity is equal to intensity due to individual slit $I_0$ Then the distance of point P from central maximum is $(\lambda= 6000 A^{\circ})$

answered Feb 19, 2014 by meena.p

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Two beam of light having intensities $I$ and $4I$ interfere to produce a fringe pattern on a screen . The phase difference between beams is $ \large\frac{\pi}{2}$ at point A and n at point B. Then the difference between resultant intensities at A and B is

answered Feb 19, 2014 by meena.p

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In a YDSE , 12 fringes are observed to be formed in a certain segment of screen when light of wavelength $600\; nm$ is used. If the wavelength of length is changed to $400\; nm$ , number of fringes observed in same segment of screen in given by

answered Feb 19, 2014 by meena.p

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When a beam of light with wave length $\lambda= 6000 A, $ travelling in air, enters a glass medium whose refractive index is 1.5 then,

answered Feb 19, 2014 by meena.p

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In the ideal YDSE , when a glass plate $(refractive index\;1.5)$ of thickness t is introduced in path of one of interfering beams (wave - length $\lambda$) the intensity at position where central maximum occurred preciously remains unchanged . The minimum thickness of glass plate is :

answered Feb 18, 2014 by meena.p

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In a YDSE $\lambda =60 \;nm\; D= 2m\;\lambda=6 mm$. Find the positions of a point lying b/w third maxima and third minima where the intensity in three - fourth of maximum intensity on the screen .

answered Feb 14, 2014 by meena.p

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When the screen is moved away from plane of slits in YDSE then the effect on interference fringes is

answered Feb 14, 2014 by meena.p

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In an interference arrangement similar to YDSE , Slits $S_1\;and \;S_2$ are illuminated with coherent microwave sources and are synchronized to have zero phase difference The slits are separates by distance $d= 150 \;m$. The intensity $I_0$ is measured as a function of $\theta$ where $\theta$ is defined as shown. If $I _0$ is max intensity, calculate $I_0$ for $\theta=90^{\circ}$

answered Feb 14, 2014 by meena.p

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In a modified YDSE a monochromatic uniform and parallel beam of light of wavelength 6000 A and intensity $\bigg(\large\frac{10}{\pi}\bigg) \large\frac{w}{m^2}$ is incident normally on two circular operates A and B of radii $0.001\;m $ and $0.002\;m$ respectively. A perfectly transparent film of thickness $2000 A^{\circ}$ and refractive index $1.5 $ for wavelength $6000\;A^{\circ}$ is placed in front of aperture A. Calculate the pour (in waters) received at Focal spot F of lens. The lens is symmetrically placed with respect to aperture. Assume $10 \%$ of power received by each aperture goes in original direction and is bought to focal speet.

answered Feb 13, 2014 by meena.p

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A beam of light consisting of two wavelength $6500 A^{\circ}$ and $5200 A^{\circ}$ is used to obtain interference fringes in a young's double slit exp. Then what is the distance from central maxima where the bright fringes due to both wavelength coincides? The distance between slits is 2 mm and distance between plane of slits and screen is 120 cm

answered Feb 13, 2014 by meena.p

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In a YDSE with $D= 1m,d=1mm$ light of wave length $500 \;nm$ is incident at an angle of $0.57^{\circ}$ with respect to axis of symmetry of experimental set up. If centre of symmetry of screen is 0. Then the intensity at point 0 in terms of intensity of central maxima $I_0$ is

answered Feb 13, 2014 by meena.p

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In a YDSE with $d= 1mm$ and $D= 1m$ slabs of $(t= 1 \mu m , \mu =3)$ and $(t=0.5\;\mu m , \mu =2) $ are introduced in front of upper and lower slit respectively . Then the shift in fringe pattern is :-

answered Feb 13, 2014 by meena.p

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White light is used in a YDSE with $D= 1m$ and $d= 0.9 mm$ .Light reaching the screen at position $y= 1 mm$ is passed through a prism and its spectrum is obtained. The missing lines in the visible region of this spectrum is :-

answered Feb 13, 2014 by meena.p

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Monochromatic light of wavelength $5000\;A^{\circ} $ is used in Y.D.S.E with slit- width $d= 1 mm$distance between screen and slits $D=1\;m$ Find the distance of 1000 th maxima

answered Feb 13, 2014 by meena.p

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Monochromatic light of wavelength $5000\;A^{\circ} $ is used in Y.D.S.E with slit- width $d= 1 mm$distance between screen and slits $D=1\;m$ .Then the distance of 5th minima from central maxima on screen is :-

answered Feb 13, 2014 by meena.p

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Find the maxima and minima obtained on screen in a $YDSE, D= 1m,d=1mm$ and $ \lambda=\large\frac{1}{2}\;mm$

answered Feb 13, 2014 by meena.p

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In a YDSE, $D = 1m \; d= 1mm$ and $\lambda =\large\frac{1}{2}$$mm$ Then the distance between the first and central maxima on screen

answered Feb 13, 2014 by meena.p

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Light from two sources , each of same frequency and travelling in same direction. but with intensity in ratio 4:1 interface. Find ratio of maximum to minimum intensity.

answered Feb 13, 2014 by meena.p

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$S_1$ and $S_2$ are two sources of light which produce individually disturbance at a point P given by $\in _1=3 \sin wt,\;\in _2 =4 \cos wt$ Assuming $\overrightarrow {\in_1}$ and $\overrightarrow{\in_2}$ to be along the same line then result of their superposition is

answered Feb 13, 2014 by meena.p

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A plate of thickness x made of refractive index $\mu $ is placed in front of one of the slits in a double slit experiment. What should be minimum thickness x . so that the central maxima turns to fringe with minimum intensity

answered Jan 24, 2014 by meena.p

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Two waves have a phase difference of $\pi $. and they have light intensities I and 9I. What will be the resultant intensity .

answered Jan 24, 2014 by meena.p

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Find the width of central maxima given $\lambda = 5 \times 10^{-5}\;cm$ slit separation $d= 0.15 \;cm$ and distance between screen and slit $D= 2.1 \;m$

answered Jan 24, 2014 by meena.p

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An unpolarised light is incident on a glass plate at polarizing angle $57^{\circ}$ with the normal on a glass plane. The reflected light will be

answered Jan 24, 2014 by meena.p

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In Young's double slit experiment the distance between adjacent fringe is x and L is distance between slit and screen. If d is split separation , then wave length is

answered Jan 24, 2014 by meena.p

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An interference pattern is observed in a young 's double slit experiment in air. Now this chamber is evacuated and the same light is used we will see .

answered Jan 24, 2014 by meena.p

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Wave nature of light explains the phenomenon of

answered Jan 24, 2014 by meena.p

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In Lloyd's single mirror experiment A light wave emitted directly from sources s interferes with a wave reflected from a mirror M. The interference pattern is formed on the screen which is kept perpendicular to the mirror and at a distance. $D=1 m$ from the source as shown . If the sources is at a distance of 1 mm from the plane of the mirror what is the fringe width when monochromatic light of 600 nm is incident from the sources

answered Jan 24, 2014 by meena.p

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