Wave Optics · Physics · MHT CET
MCQ (Single Correct Answer)
The two coherent sources produce interference with intensity ratio ' $b$ '. In the interference pattern, the ratio $\frac{I_{\text {max }}+I_{\text {min }}}{I_{\text {max }}-I_{\text {min }}}$ will be
According to Huygen's wave theory of light, which one of the following statements is not correct?
Interference fringes are produced on the screen by using two light sources of intensities I and 9I. The phase difference between the beams is $\pi / 2$ at point P and $\pi$ at point Q on the screen. The difference between the resultant intensities at points P and Q is $\left(\cos 90^{\circ}=0, \cos \pi=-1\right)$
In Young's double slit experiment, in an interference pattern, a minimum is observed exactly in front of one slit. The distance between the two coherent sources is d and $\mathrm{D}_{\text { }}$ is the distance between source and screen. The possible wavelengths used are proportional to
Three polarised sheets are co-axially placed. Pass axis of polaroids 2 and 3 make $30^{\circ}$ and $90^{\circ}$ with pass axis of polaroid sheet. If $\mathrm{I}_0$ is the intensity of unpolarised light entering sheet 1 , the intensity of the emergent light through sheet 3 is
$$ \left(\cos 30^{\circ}=\sqrt{3} / 2, \cos 90^{\circ}=0, \cos 60^{\circ}=1 / 2\right) $$
Four polaroids are placed such that the optic axis of each is inclined at an angle of $30^{\circ}$ the optic axis of the preceding one. If unpolarised light of intensity ' $\mathrm{I}_0$ ' falls on the first polaroid, the intensity of light transmitted from the fourth polaroid is $\left[\cos 30^{\circ}=\frac{\sqrt{3}}{2}\right]$
The apparent wavelength of light from a star moving away from the earth is $0.02 \%$ more than the actual wavelength. The velocity of star is $\left[\mathrm{c}=\right.$ velocity of light $\left.=3 \times 10^8 \mathrm{~m} / \mathrm{s}\right]$
In Young's double slit experiment with monochromatic light of wavelength 600 nm , the distance between the slits is $10^{-3} \mathrm{~m}$. For changing the fringe width by $3 \times 10^{-5} \mathrm{~m}$
a. the screen is moved away from the slit by 5 cm .
b. the screen is moved 5 cm towards the slits.
c. the screen is moved 3 cm towards the slits.
d. the screen is moved away from the slits by 3 cm .
A ray of light of intensity ' I ' is incident on a parallel glass slab at a point ' $A$ ' as shown in figure. It undergoes partial reflection and refraction. At each reflection $25 \%$ of incident energy is reflected. The rays $A B$ and $A B$ undergo interference. The ratio $\frac{\mathrm{I}_{\text {max }}}{\mathrm{I}_{\text {min }}}$ is
In Young's double slit experiment, the distance between screen and aperture is 1 m . The slit width is 2 mm . Light of $6000 \mathop {\rm{A}}\limits^{\rm{o}}$ is used. If a thin glass plate ( $\mu=1.5$ ) of thickness 0.04 mm is placed over one of the slits, then there will be a lateral displacement of the fringes by
In Young's double slit experiment, when light of wavelength 600 nm is used, 18 fringes are observed on the screen. If the wavelength of light is changed to 400 nm , the number of fringes observed on the screen is
In Young's double slit experiment, for the $n$th dark fringe ( $\mathrm{n}=1,2,3 \ldots$ ) the phase difference of the interfering waves in radian will be
In Young's double slit experiment, the intensity on screen at a point where path difference is $\frac{\lambda}{4}$ is $\frac{K}{2}$. The intensity at a point when path difference is ' $\lambda$ ' will be
In Fraunhofer diffraction pattern, slit width is 0.2 mm and screen is at 2 m away from the lens. If the distance between the first minimum on either side of the central maximum is 1 cm , the wavelength of light used is
In Young's double slit experiment let 'd' be the distance between two slits and 'D' be the distance between the slits and the screen. Using a monochromatic source of wavelength ' $\lambda$ ', in an interference pattern, third minimum is observed exactly in front of one of the slits. If at the same point on the screen first minimum is to be obtained, the required change in the wavelength is [ $\mathrm{d} \& \mathrm{D}$ are not changed].
Three identical polaroids $P_1, P_2$ and $P_3$ are placed one after another. The pass axis of $P_2$ and $\mathrm{P}_3$ are inclined at an angle of $60^{\circ}$ and $90^{\circ}$ with respect to axis of $\mathrm{P}_1$. The source has an intensity $256 \mathrm{~W} / \mathrm{m}^2$. The intensity of light at point ' O ' is $\left(\cos 30^{\circ}=\sqrt{3} / 2, \cos 60^{\circ}=0.5\right)$
In a single slit diffraction experiment, for a wavelength of light ' $\lambda$ ', half-angular width of the principle maxima is ' $\theta$ '. Also for wavelength of light $\mathrm{p} \lambda$, the half angular width of the principle maxima is $q \theta$. The ratio of the halfangular widths of the first secondary maxima in the first case to second case will be
In a double slit experiment, the distance between slits is increased 10 times, whereas their distance from screen is halved, the fringe width
The angular separation of the central maximum in the Fraunhofer diffraction pattern is measured. The slit is illuminated by the light of wavelength $6000 \mathop A\limits^o$. If the slit is illuminated by light of another wavelength, the angular separation decreases by $20 \%$. The wavelength of light used is
In Young's double slit experiment, intensity at a point is $\left(\frac{1}{4}\right)$ of the maximum intensity. The angular position of this point is
Two sound waves each of wavelength ' $\lambda$ ' and having the same amplitude ' $A$ ' from two source ' $\mathrm{S}_1$ ' and ' $\mathrm{S}_2$ ' interfere at a point P . If the path difference, $\mathrm{S}_2 \mathrm{P}-\mathrm{S}_1 \mathrm{P}=\lambda / 3$ then the amplitude of resultant wave at point ' P ' will be $\left[\cos \left(120^{\circ}\right)=-0.5\right]$
Sodium light $\left(\lambda=6 \times 10^{-7} \mathrm{~m}\right)$ is used to produce interference pattern. The observed fringe width is 0.12 mm . The angle between the two wave trains is
A plate of refractive index 1.6 is introduced in the path of light from one of the slits in Young's double slit experiment then
In Young's double slit experiment, the intensity of light at a point on the screen where the path difference is $\lambda$ is x units, $\lambda$ being the wavelength of light used. The intensity at a point where the path difference is $\frac{\lambda}{4}$ will be $\left(\cos 2 \pi=1, \cos \frac{\pi}{2}=0\right)$
In double slit experiment, instead of taking slits of equal widths, one slit is made twice as wide as the other. Then in interference pattern
In biprism experiment, the fringe width is 0.6 mm . The distance between $6^{\text {th }}$ dark fringe and $8^{\text {th }}$ bright fringe on the same side of central bright fringe is
In Young's double slit experiment, 'I' is the minimum intensity and ' $I_1$ ' is the intensity at a point where the path difference is $\frac{\lambda}{4}$ where ' $\lambda$ ' is the wavelength of light used. The ratio $I_1 \mathrm{I}_1$ is (Intensities of the two interfering waves are same) $\left(\cos 0^{\circ}=1, \cos 90^{\circ}=0\right)$
Considering interference between two sources of intensities ' I ' and ' 4 I ', the intensity at a point where the phase difference is $\pi$ is $(\cos \pi=-1)$
The phase difference between two waves giving rise to dark fringe in Young's double slit experiment is ( n is the integer)
How is the interference pattern affected when violet light replaces sodium light?
In Fraunhofer diffraction pattern, slitwidth is 0.5 mm and screen is at 2 m away from the lens. If wavelength of light used is $5500\mathop A\limits^o$, then the distance between the first minimum on either side of the central maximum is ( $\theta$ is small and measured in radian)
Two identical light waves having phase difference $\phi$ propagate in same direction. When they superpose, the intensity of resultant wave is proportional to
In Young's double slit experiment, the distance between the two coherent sources is ' d ' and the distance between the source and screen is ' D '. When the wavelength $(\lambda)$ of light source used is $\frac{d^2}{3 D}$, then $n^{\text {th }}$ dark fringe is observed on the screen, exactly in front of one of the slits. The value of ' $n$ ' is
Two light rays having the same wavelength ' $\lambda$ ' in vacuum are in phase initially. Then, the first ray travels a path ' $\mathrm{L}_1$ ' through a medium of refractive index ' $\mu_1$ ' while the second ray travels a path of length ' $L_2$ ' through a medium of refractive index ' $\mu_2$ '. The two waves are then combined to observe interference. The phase difference between the two waves is
In Young's double slit experiment, the slits are separated by 0.6 mm and screen is placed at a distance of 1.2 m from slit. It is observed that the tenth bright fringe is at a distance of 8.85 mm from the third dark fringe on the same side. The wavelength of light used is
In a diffraction pattern due to single slit of width ' $a$ ', the first minimum is observed at an angle $30^{\circ}$ when light of wavelength $5000 \mathop A\limits^o$ is incident on the slit. The first secondary maximum is observed at an angle $\left[\sin 30=\frac{1}{2}\right]$
In biprism experiment, if $5^{\text {th }}$ bright band with wavelength $\lambda_1$ coincides with $6^{\text {th }}$ dark band with wavelength $\lambda_2$ then the ratio $\left(\lambda_1 / \lambda_2\right)$ is
In young's double slit experiment, the $\mathrm{n}^{\text {th }}$ maximum of wavelength $\lambda_1$ is at a distance of $y_1$ from the central maximum. When the wavelength of the source is changed to $\lambda_2,\left(\frac{\mathrm{n}}{3}\right)^{\text {th }}$ maximum is at a distance of $y_2$ from its central maximum. The ratio $\frac{y_1}{y_2}$ is
In the Young's double slit experiment, the intensity at a point on the screen, where the path difference is $\lambda(\lambda=$ wavelength $)$ is $\beta$. The intensity at a point where the path difference is $\lambda / 3$, will be $\left.\cos \frac{\pi}{3}=1 / 2\right]$
The fringe width in an interference pattern is ' X '. The distance between the sixth dark fringe from one side of central bright band to the fourth bright fringe on other side is
In Young's double slit experiment using monochromatic light of wavelength ' $\lambda$ ', the maximum intensity of light at a point on the screen is ' K ' units. The intensity of light at a point where the path difference is $\frac{\lambda}{6}$ ' is $\left(\cos 60^{\circ}=\sin 30^{\circ}=0.5, \sin 60^{\circ}=\cos 30^{\circ}=\sqrt{3} / 2\right)$
A wavefront is a surface
Two wavelength 590 nm and 596 nm of sodium light are used one after other, to study the diffraction taking place at a single slit of aperture 2.4 mm . The distance between the slit and screen is 2 m . The separation between the positions of first secondary maximum of the diffraction pattern obtained in the two cases is
A parallel beam of light of intensity $I_0$ is incident on a glass plate, $25 \%$ of light is reflected by upper surface and $50 \%$ of light is reflected from lower surface. The ratio of maximum to minimum intensity in interference region of reflected rays is
A single slit of width $d$ is illuminated by violet light of wavelength 400 nm and the width of the diffraction pattern is measured as ' Y '. When half of the slit width is covered and illuminated by yellow light of wavelength 600 nm , the width of the diffraction pattern is
In a biprism experiment, monochromatic light of wavelength ' $\gamma$ ' is used. The distance between the two coherent sources ' $d$ ' is kept constant. If the distance between slit and eyepiece ' $D$ ' is varied as $D_1, D_2, D_3, D_4$ and corresponding measured fringe widths are $\mathrm{W}_1, \mathrm{~W}_2, \mathrm{~W}_3, \mathrm{~W}_4$ then
Three identical polaroids $P_1, P_2$ and $P_3$ are placed one after another. The pass axis of $P_2$ and $P_3$ are inclined at an angle $60^{\circ}$ and $90^{\circ}$ with respect to axis of $P_1$. The source has an intensity $I_0$. The intensity of transmitted light through $P_3$ is $\left(\cos 60^{\circ}=0.5, \cos 30^{\circ}=\frac{\sqrt{3}}{2}\right)$
In Young's double slit experiment, in an interference pattern, second minimum is observed exactly in front of one slit. The distance between the two coherent sources is ' $d$ ' and the distance between the source and screen is ' $D$ '. The wave length of light $(\lambda)$ used is
A screen is placed at 50 cm from a single slit, which is illuminated with light of wavelength 600 nm . If separation between the $1^{\text {st }}$ and $3^{\text {rd }}$ minima in the diffraction pattern is 3 mm then slit width is
In Young's double slit experiment using monochromatic light of wavelength ' $\lambda$ ', the intensity of light at a point on the screen where path difference ' $\lambda$ ' is K units. The intensity of light at a point where the path difference is $\frac{\lambda}{6}$ is $\left[\cos \frac{\pi}{6}=\sin \frac{\pi}{3}=\frac{\sqrt{3}}{2}\right]$
In an interference experiment, the $\mathrm{n}^{\text {th }}$ bright fringe for light of wavelength $\lambda_1(\mathrm{n}=0,1,2,3 \ldots)$ coincides with the $\mathrm{m}^{\text {th }}$ dark fringe for light of wavelength $\lambda_2(\mathrm{~m}=1,2,3 \ldots)$. The ratio $\frac{\lambda_1}{\lambda_2}$ is
A single slit diffraction pattern is formed with light of wavelength $6195 \mathop A\limits^o$. The second secondary maximum for this wavelength coincides with the third secondary maximum in the pattern for light of wavelength ' $\lambda_0$ '. The value of ' $\lambda_0$ ' is
When wavefronts pass from denser medium to rarer medium, the width of the wavefront
A diffraction pattern is obtained using a beam of red light. If red light is replaced by blue light then
The intensity ratio of the maxima and minima in an interference pattern produced by two coherent sources of light is $9: 1$. The intensities of the light sources used are in the ratio
Two points separated by a distance of 0.1 mm can just be seen in microscope when light of wavelength $6000 \mathop A\limits^o $ is used. If the light of wavelength $4800 \mathop A\limits^o $ is used, the limit of resolution will become
The intensity of light coming from one of the slits in Young's double slit experiment is double the intensity from the other slit. The ratio of the maximum intensity to the minimum intensity in the interference fringe pattern observed is
In a Young's double slit experiment, the source is white light. One of the holes is covered by a red filter and another by a blue filter. In this case
On replacing a thin film of mica of thickness $$12 \times 10^{-5} \mathrm{~cm}$$ in the path of one of the interfering beams in Young's double slit experiment using monochromatic light, the fringe pattern shifts through a distance equal to the width of bright fringe. If $$\lambda=6 \times 10^{-5} \mathrm{~cm}$$, the refractive index of mica is
When two light waves each of amplitude '$$A$$' and having a phase difference of $$\frac{\pi}{2}$$ superimposed then the amplitude of resultant wave is
Two wavelengths of sodium light $$590 \mathrm{~nm}$$ and $$596 \mathrm{~nm}$$ are used one after another to study diffraction due to single slit of aperture $$2 \times 10^{-6} \mathrm{~m}$$. The distance between the slit and the screen is $$1.5 \mathrm{~m}$$. The separation between the positions of first maximum of the diffraction pattern obtained in the two cases is
The diffraction fringes obtained by a single slit are of
In Young's double slit experiment, $$8^{\text {th }}$$ maximum with wavelength '$$\lambda_1$$' is at a distance '$$d_1$$' from the central maximum and $$6^{\text {th }}$$ maximum with wavelength '$$\lambda_2$$' is at a distance '$$\mathrm{d}_2$$'. Then $$\frac{\mathrm{d}_2}{\mathrm{~d}_1}$$ is
If $$\mathrm{I}_0$$ is the intensity of the principal maximum in the single slit diffraction pattern, then what will be the intensity when the slit width is doubled?
Light of wavelength $$5000 \mathop A\limits^o$$ is incident normally on a slit. The first minimum of the diffraction pattern is observed to lie at a distance of $$5 \mathrm{~mm}$$ from the central maximum on a screen placed at a distance of $$2 \mathrm{~m}$$ from the slit. The width of the slit is
The path difference between two identical light waves at a point $$Q$$ on the screen is $$3 \mu \mathrm{m}$$. If wavelength of the waves is $$5000 \mathop A\limits^o$$, then at point $$Q$$ there is
Of the two slits producing interference in Young's experiment, one is covered with glass so that light intensity passing is reduced to $$50 \%$$. Which of the following is correct?
In a biprism experiment, monochromatic light of wavelength '$$\lambda$$' is used. The distance between two coherent sources '$$\mathrm{d}$$' is kept constant. If the distance between slit and eyepiece '$$\mathrm{D}$$' is varied as $$D_1, D_2, D_3 \& D_4$$ and corresponding measured fringe widths are $$Z_1, Z_2, Z_3$$ and $$Z_4$$ then
$$\mathrm{A}$$ and $$\mathrm{B}$$ are two interfering sources where $$\mathrm{A}$$ is ahead in phase by $$54^{\circ}$$ relative to B. The observation is taken from point $$\mathrm{P}$$ such that PB $$-$$ PA = 2.5 $$\lambda$$. Then the phase difference between the waves from A and B reaching point P is (in rad)
The ratio of intensities of two points on a screen in Young's double slit experiment when waves from the two slits have a path difference of $$\frac{\lambda}{4}$$ and $$\frac{\lambda}{6}$$ is
$$\left(\cos 90^{\circ}=0, \cos 60^{\circ}=0.5\right)$$
In Young's double slit experiment when a glass plate of refractive index 1.44 is introduced in the path of one of the interfering beams, the fringes are displaced by a distance '$$y$$'. If this plate is replaced by another plate of same thickness but of refractive index 1.66, the fringes will be displaced by a distance
One of the slits in Young's double slit experiment is covered with a transparent sheet of thickness $$2.9 \times 10^{-3} \mathrm{~cm}$$. The central fringe shifts to a position originally occupied by the $$25^{\text {th }}$$ bright fringe. If $$\lambda=5800$$ $$\mathop A\limits^o $$, the refractive index of the sheet is
In Young's double slit experiment the intensities at two points, for the path difference $$\frac{\lambda}{4}$$ and $$\frac{\lambda}{3}$$ ($$\lambda=$$ wavelength of light used) are $$I_1$$ and $$I_2$$ respectively. If $$\mathrm{I}_0$$ denotes the intensity produced by each one of the individual slits then $$\frac{\mathrm{I}_1+\mathrm{I}_2}{\mathrm{I}_0}$$ is equal to $$\left(\cos 60^{\circ}=0.5, \cos 45^{\circ}=\frac{1}{\sqrt{2}}\right)$$
In two separate setups for Biprism experiment using same wavelength, fringes of equal width are obtained. If ratio of slit separation is $$2: 3$$ then the ratio of the distance between the slit and screen in the two setups is
A beam of light is incident on a glass plate at an angle of $$60^{\circ}$$. The reflected ray is polarized. If angle of incidence is $$45^{\circ}$$ then angle of refraction is
A beam of light of wavelength $$600 \mathrm{~nm}$$ from a distant source falls on a single slit $$1 \mathrm{~mm}$$ wide and the resulting diffraction pattern is observed on a screen $$2 \mathrm{~m}$$ away. The distance between the first dark fringe on either side of the central bright fringe is
In Young's double slit experiment, the fifth maximum with wavelength '$$\lambda_1$$' is at a distance '$$y_1$$' and the same maximum with wavelength '$$\lambda_2$$' is at a distance '$$y_2$$' measured from the central bright band. Then $$\frac{y_1}{y_2}$$ is equal to [D and $$d$$ are constant]
In Young's double slit experiment, green light is incident on two slits. The interference pattern is observed on a screen. Which one of the following changes would cause the observed fringes to be more closely spaced?
A double slit experiment is immersed in water of refractive index 1.33. The slit separation is $$1 \mathrm{~mm}$$, distance between slit and screen is $$1.33 \mathrm{~m}$$ The slits are illuminated by a light of wavelength $$6300 \mathop A\limits^o$$. The fringe width is
In the experiment of diffraction due to a single slit, if the slit width is decreased, the width of the central maximum
In biprism experiment, if $$5^{\text {th }}$$ bright band with wavelength $$\lambda_1^{\prime}$$ coincides with $$6^{\text {th }}$$ dark band with wavelength $$\lambda_2{ }^{\prime}$$ then the ratio $$\left(\frac{\lambda_2}{\lambda_1}\right)$$ is
In Young's double slit experiment, the two slits are 'd' distance apart. Interference pattern is observed on a screen at a distance 'D' from the slits. A dark fringe is observed on a screen directly opposite to one of the slits. The wavelength of light is
A parallel beam of monochromatic light falls normally on a single narrow slit. The angular width of the central maximum in the resulting diffraction pattern
Light waves from two coherent sources arrive at two points on a screen with path difference of zero and $$\frac{\lambda^{\prime}}{2}$$. The ratio of intensities at the points is $$\left(\cos 0^{\circ}=1, \cos \pi=-1\right)$$
A person is observing a bacteria through a compound microscope. For better observation and to improve its resolving power he should
In Young's double slit experiment the separation between the slits is doubled without changing other setting of the experiment to obtain same fringe width, the distance 'D' of the screen from slit should be made
Two sources of light $$0.6 \mathrm{~mm}$$ apart and screen is placed at a distance of $$1.2 \mathrm{~m}$$ from them. A light of wavelength $$6000\,\mathop A\limits^o$$ used. Then the phase difference between the two light waves interfering on the screen at a point at a distance $$3 \mathrm{~mm}$$ from central bright band is
Light of wavelength ',$$\lambda$$' is incident on a slit of width '$$\mathrm{d}$$'. The resulting diffraction pattern is observed on a screen at a distance '$$D$$'. The linear width of the principal maximum is then equal to the width of the slit if $$D$$ equals
In Young's double slit experiment, the wavelength of light used is '$$\lambda$$'. The intensity at a point is '$$\mathrm{I}$$' where path difference is $$\left(\frac{\lambda}{4}\right)$$. If $$I_0$$ denotes the maximum intensity, then the ratio $$\left(\frac{\mathrm{I}}{\mathrm{I}_0}\right)$$ is
$$\left(\sin \frac{\pi}{4}=\cos \frac{\pi}{4}=\frac{1}{\sqrt{2}}\right)$$
In Young's double slit experiment, the fringe width is $$2 \mathrm{~mm}$$. The separation between the $$13^{\text {th }}$$ bright fringe and the $$4^{\text {th }}$$ dark fringe from the centre of the screen on same side will be
A beam of unpolarized light passes through a tourmaline crystal A and then it passes through a second tourmaline crystal B oriented so that its principal plane is parallel to that of A. The intensity of emergent light is $$I_0$$. Now B is rotated by $$45^{\circ}$$ about the ray. The emergent light will have intensity $$\left(\cos 45^{\circ}=\frac{1}{\sqrt{2}}\right)$$
In a diffraction pattern due to single slit of width '$$a$$', the first minimum is observed at an angle of $$30^{\circ}$$ when the light of wavelength $$5400 \mathop A\limits^o$$ is incident on the slit. The first secondary maximum is observed at an angle of $$\left(\sin 30^{\circ}=\frac{1}{2}\right)$$
In a single slit experiment, the width of the slit is doubled. Which one of the following statements is correct?
The rays of different colours fail to converge at a point after passing through a thick converging lens. This defect is called
A parallel beam of monochromatic light falls normally on a single narrow slit. The angular width of the central maximum in the resulting diffraction pattern
In a Fraunhofer diffraction at a single slit of width 'd' and incident light of wavelength $$5500 \mathop A\limits^o$$, the first minimum is observed at an angle $$30^{\circ}$$. The first secondary maxima is observed at an angle $$\theta$$, equal to
Two monochromatic beams of intensities I and 4 I respectively are superposed to form a steady interference pattern. The maximum and minimum intensities in the pattern are
The path difference between two interfering light waves meeting at a point on the screen is $$\left(\frac{57}{2}\right) \lambda$$. The bond obtained at that point is
In Young's double slit experiment, in an interference pattern, a minimum is observed exactly in front of one slit. The distance between the two coherent sources is '$$\mathrm{d}$$' and '$$\mathrm{D}$$' is the distance between the source and screen. The possible wavelengths used are inversely proportional to
A beam of light having wavelength $$5400 \mathrm{~A}$$ from a distant source falls on a single slit $$0.96 \mathrm{~mm}$$ wide and the resultant diffraction pattern is observed on a screen $$2 \mathrm{~m}$$ away. What is the distance between the first dark fringe on either side of central bright fringe?
Two beams of light having intensities I and 4I interfere to produce a fringe pattern on a screen. The phase difference between the beams is $$\pi / 2$$ at point $$\mathrm{A}$$ and $$\pi$$ at point $$\mathrm{B}$$. Then the difference between the resultant intensities at $$\mathrm{A}$$ and $$\mathrm{B}$$ is
In Young's double slit experiment, the intensity at a point where path difference is $$\frac{\lambda}{6}$$ ($$\lambda$$ being the wavelength of light used) is $$I^{\prime}$$. If '$$I_0$$' denotes the maximum intensity, then $$\frac{I}{I_0}$$ is equal to $$\left(\cos 0^{\circ}=1, \cos 60^{\circ}=\frac{1}{\lambda}\right)$$
In Young's double slit experiment, the distance of $$\mathrm{n}^{\text {th }}$$ dark band from the central bright band in terms of bandwidth '$$\beta$$' is
In biprism experiment, $$6^{\text {th }}$$ bright band with wavelength '$$\lambda_1$$' coincides with $$7^{\text {th }}$$ dark band with wavelength '$$\lambda_2$$' then the ratio $$\lambda_1: \lambda_2$$ is (other setting remains the same)
In Young's experiment with a monochromatic source and two slits, one of the slits is covered with black opaque paper, the fringes will
In the interference experiment using a biprism, the distance of the slits from the screen is increased by $$25 \%$$ and the separation between the slits is halved. If '$$W$$' represents the original fringewidth, the new fringewidth is
In biprims experiment, the $$4^{\text {th }}$$ dark band is formed opposite to one of the slits. The wavelength of light used is $$(\mathrm{d}=$$ distance between the slits, $$\mathrm{D}=$$ distance between scource and the screen)
In Young's double slit experiment using monochromatic light of wavelength '$$\lambda$$', the maximum intensity of light at a point on the screen is $$\mathrm{K}$$ units. The intensity of light at point where the path difference is $$\frac{\lambda}{3}$$ is
$$\left[\cos 60^{\circ}=\sin 30^{\circ}=\frac{1}{2}\right]$$
If two sources emit light waves of different amplitudes then
In Young's double slit experiment, the $$10^{\text {th }}$$ maximum of wavelength '$$\lambda_1$$' is at a distance of '$$Y_1$$' from the central maximum. When the wavelength of the source is changed to '$$\lambda_2$$', $$5^{th}$$ maximum is at a distance '$$Y_2$$' from the central maximum. The ratio $$\frac{Y_1}{Y_2}$$ is
A single slit diffraction pattern is formed with white light. For what wavelength of light the $$3^{\text {rd }}$$ secondary maximum in diffraction pattern coincides with the $$2^{\text {nd }}$$ secondary maximum in the pattern of red light of wavelength 6000 $$\mathop A\limits^o $$ ?
The width of central maximum of a diffraction pattern on a single slit does not depend upon
Two coherent sources of wavelength '$$\lambda$$' produce steady interference pattern. The path difference corresponding to 10$$^{th}$$ order maximum will be
In Young's experiment, fringes are obtained on a screen placed at a distance $$75 \mathrm{~cm}$$ from the slits. When the separation between two narrow slits is doubled, then the fringe width is decreased. In order to obtain the initial fringe width, the screen should be moved through.
Two coherent sources 'P' and 'Q' produce interference at point 'A' on the screen, where there is a dark band which is formed between 4th and 5th bright band. Wavelength of light used is 6000 $$\mathop A\limits^o $$. The path difference PA and QA is
In diffraction experiment, from a single slit, the angular width of central maximum does NOT depend upon
In biprism experiment, 21 fringes are observed in a given region using light of wavelength 4800 $$\mathop A\limits^o $$. If light of wavelength 5600 $$\mathop A\limits^o $$ is used, the number of fringes in the same region will be
A double slit experiment is immersed in water of refractive index 1.33. The slit separationis 1 $$\mathrm{mm}$$ and the distance between slit and screen is $$1.33 \mathrm{~m}$$. The slits are illuminated by a light of wavelength $$6300\,\mathop A\limits^o $$. The fringewidth is
In a single slit diffraction pattern, the distance between the first minimum on the left and the first minimum on the right is $$5 \mathrm{~mm}$$. The screen on which the diffraction pattern is obtained is at a distance of $$80 \mathrm{~cm}$$ from the slit. The wavelength used is 6000 $$\mathop A\limits^o $$. The width of the silt is
In Young's double slit experiment, with a source of light having wavelength $$6300 \mathop A\limits^o$$, the first maxima will occur when the
In Young's double slit experiment, the intensity at a point where the path difference is $$\frac{\lambda}{4}$$ [ $$\lambda$$ is wavelength of light used] is '$$\mathrm{I}$$'. If '$$\mathrm{I}_0$$' is the maximum intensity then $$\frac{\mathrm{I}}{\mathrm{I}_0}$$ is equal to $$\left[\cos \frac{\pi}{4}=\sin \frac{\pi}{4}=\frac{1}{\sqrt{2}}\right]$$
In Young's double slit experiment, the '$$\mathrm{n^{th}}$$' maximum of wavelength '$$\lambda_1$$' is at a distance '$$\mathrm{y_1}$$' from the central maximum. When the wavelength of the source is changed to '$$\lambda_2$$', $$\left(\frac{\mathrm{n}}{2}\right)^{\text {th }}$$ maximum is at a distance of '$$\mathrm{y_2}$$' from its central maximum. The ratio $$\frac{y_1}{y_2}$$ is
Light of wavelength '$$\lambda$$' is incident on a single slit of width 'a' and the distance between slit and screen is 'D'. In diffraction pattern, if slit width is equal to the width of the central maximum then $$\mathrm{D}=$$
In Fraunhofer diffraction pattern, slit width is 0.2 mm and screen is at 2m away from the lens. If wavelength of light used is 5000$$\mathop A\limits^o $$ then the distance between the first minimum on either side of the central maximum is ($$\theta$$ is small and measured in radian)
A graph is plotted between the fringe-width Z and the distance D between the slit and eye-piece, keeping other adjustment same. The correct graph is
(A) 
(B) 
(C) 
(D) 
The Brewster's angle for the glass-air interface is $(54.74)^{\circ}$. If a ray of light passing from air to glass strickes at an angle of incidence $45^{\circ}$, then the angle of refraction is
$$\left[\tan (54.74)^{\circ}=\sqrt{2}, \sin 45=\frac{1}{\sqrt{2}}\right]$$
A light wave of wavelength $$\lambda$$ is incident on a slit of width $$d$$. The resulting diffraction pattern is observed on a screen at a distance $$D$$. If linear width of the principal maxima is equal to the width of the slit, then the distance $$D$$ is
When wavelength of light used in optical instruments A and B are 4500$$\mathop A\limits^o $$ and 6000$$\mathop A\limits^o $$ respectively, the ratio of resolving power of A to B will be
In diffraction experiment, from a single slit, the angular width of the central maxima does not depend upon
In Young's double slit experiment green light is incident on the two slits. The interference pattern is observed on a screen. Which one of the following changes would cause the observed fringes to be more closely spaced?
When a photon enters glass from air, which one of the following quantity does not change?
In Young's double slit experiment fifth dark fringe is formed opposite to one of the slit. IID is the distance between the slits and the screen and $d$ is the separation between the slits, then the wavelength of light used is
The phenomenon of interference is based on
Light of wavelength ' $\lambda$ ' is incident on a single slit of width ' $a$ ' and the distance between slit and screen is ' $D$ '. In diffraction pattern, if slit width is equal to the width of the central maximum then ' $D$ ' is equal to
The luminous border that surrounds the profile of a mountain just before sun rises behind it, is an example of
In biprism experiment, the distance between source and eyepiece is 1.2 m, the distance between two virtual sources is 0.84 mm. Then the wavelength of light used if eyepiece is to be moved transversely through a distance of 2.799 cm to shift 30 fringes is
If a star emitting yellow light is accelerated towards earth, then to an observer on earth it will appear