JEE Questions for Physics Wave Optics Quiz 6 - MCQExams.com

In a Young\'s double slit experiment, the central point on the screen is
  • Bright
  • Dark
  • First bright and then dark
  • First dark and then bright
In a Young\'s double slit experiment, the fringe width is found to be 0.4 mm. If the whole apparatus is immersed in water of refractive index 4/3 without disturbing the geometrical arrangement, the new fringe width will be
  • 0.30 mm
  • 0.40 mm
  • 0.53 mm
  • 450 micron
In double slit experiment, for light of which colour the fringe width will be minimum?
  • Violet
  • Red
  • Green
  • Yellow
In Young\'s double slit interference pattern the fringe width
  • Can be changed only by changing the wavelength of incident light
  • Can be changed only by changing the separation between the two slits
  • Can be changed either by changing the wavelength or by changing the separation between the two slits
  • Is a universal constant, hence cannot be changed
In Young\'s double slit experiment, the phase difference between the light waves reaching third bright fringe from the central fringe will be (λ = 6000Å)
  • Zero
  • 2π
  • 4 π
  • 6 π
In Young\'s double slit experiment, if the widths of the slits are in the ratio 4 : 9, the ratio of the intensity at maxima to the intensity at minima will be
  • 169 : 25
  • 81 : 16
  • 25 : 1
  • 9 : 4
In Young\'s double slit experiment when wavelength used is 6000 Å and the screen is 40 cm from the slits, the fringes are 0.012 cm wide. What is the distance between the slits
  • 0.024 cm
  • 2.4 cm
  • 0.24 cm
  • 0.2 cm
In two separate set-ups of the Young\'s double slit experiment, fringes of equal width are observed when lights of wavelength in the ratio 1 : 2 are used. If the ratio of the slit separation in the two cases is 2 : 1, the ratio of the distances between the plane of the slits and the screen in the two set-ups is
  • 4 : 1
  • 1 : 1
  • 1 : 4
  • 2 : 1
In an interference experiment, the spacing between successive maxima or minima is
(Where the symbols have usual meanings)

  • Physics-Wave Optics-95503.png
  • 2)
    Physics-Wave Optics-95504.png

  • Physics-Wave Optics-95505.png

  • Physics-Wave Optics-95506.png
In Young\'s double slit experiment, a third slit is made in between the double slits. Then
  • Fringes of unequal width are formed
  • Contrast between bright and dark fringes is reduced
  • Intensity of fringes totally disappears
  • Only bright light is observed on the screen
In Young\'s double slit experiment, the fringe width is 1 × 10–4 m. If the distance between the slit and screen is doubled and the distance between the two slit is reduced to half and wavelength is change from 6.4 × 10–7m to 4.0 × 10–7m, the value of new fringe width will be
  • 0.15 × 10–4 m
  • 2.0 × 10–4 m
  • 1.25 × 10–4 m
  • 2.5 × 10–4 m
In Young\'s experiment, one slite is covered with a blue filter and the other (slit) with a yellow filter. Then the interference pattern
  • Will be blue
  • Will be yellow
  • Will be green
  • Will not be formed
Two sources give interference pattern which is observed on a screen, D distance apart from the sources. Then fringe width is 2w. If the distance D is now doubled, the fringe width will
  • Become w/2
  • Remain the same
  • Become w
  • Become 4 w
In double slit experiment, the angular width of the fringes is 0.20° for the sodium light (λ = 5890Å). In order to increase the angular width of the fringes by 10%, the necessary change in the wavelength is
  • Increase of 589 Å
  • Decrease of 589 Å
  • Increase of 6479 Å
  • Zero
In a biprism experiment, by using light of wavelength 5000 Å, 5 mm wide fringes are obtained on a screen 1.0 m away from the coherent sources. The separation between the two coherent sources is
  • 1.0 mm
  • 0.1 mm
  • 0.1 mm
  • 0.01 mm
The slits in a Young\'s double slit experiment have equal widths and the source is placed symmetrically relative to the slits. The intensity at the central fringes is I0. If one of the slits is closed, the intensity at this point will be
  • I0
  • I0 / 4
  • I0 / 2
  • 4 I0
In Young\'s double slit experiment the amplitudes of two sources are 3α and a respectively. The ratio of intensities of bright and dark fringes will be
  • 3 : 1
  • 4 : 1
  • 2 : 1
  • 9 : 1
In a Young\'s double slit experiment, the fringe width will remain same, if (D = distance between screen and plane of slits. d = separation between two slits and λ = wavelength of light used)
  • Both λ and D are doubled
  • Both d and D are doubled
  • D is doubled but d is halved
  • λ is doubled but d is halved
In a Young\'s double slit experiment the intensity at a point where the path difference λ/6 (λ being the wavelength of the light used) is I. If I0 denotes the maximum intensity, I/ I0 is equal to

  • Physics-Wave Optics-95514.png
  • 2)
    Physics-Wave Optics-95515.png

  • Physics-Wave Optics-95516.png

  • Physics-Wave Optics-95517.png
In Young\'s double slit experiment, angular width of fringes is 0.20° for sodium light of wavelength 5890 Å. If complete system is dipped in water, then angular width of fringes becomes
  • 0.11°
  • 0.15°
  • 0.22°
  • 0.30°
In Young\'s double slit experiment, the distance between the slits is 1 mm and that between slit and screen is 1 meter and 10th fringe is 5 mm away from the central bright fringe, then wavelength of light used will be
  • 5000 Å
  • 6000 Å
  • 7000 Å
  • 8000 Å
In Young\'s double slit experiment, carried out with light of wavelength λ = 5000 Å, the distance between the slits is 0.2 mm and the screen is at 200 cm from the slits. The central maximum is at x = 0. The third maximum (taking the central maximum as zeroth maximum) will be at x equal to
  • 1.67 cm
  • 1.5 cm
  • 0.5 cm
  • 5.0 cm
In a Young\'s experiment, two coherent sources are placed 0.90 mm apart and the fringes are observed one metre away. If it produces the second dark fringe at a distance of 1 mm from the central fringe, the wavelength of monochromatic light used would be
  • 60 × 10–4 cm
  • 10 × 10–4 cm
  • 10 × 10–5 cm
  • 6 × 10–5 cm
In Young\'s double slit experiment, the distance between the two slits is 0.1 mm and the wavelength of light used is 4 × 10–7 m. If the width of the fringe on the screen is 4mm, the distance between screen and slit is
  • 0.1 mm
  • 1 cm
  • 0.1 cm
  • 1 m
In Young\'s double slit experiment, the distance between sources is 1mm and distance between the screen and source is 1 m. If the fringe width on the screen is 0.06 cm, then λ =
  • 6000 Å
  • 4000 Å
  • 1200 Å
  • 2400 Å
If a torch is used in place of monochromatic light in Young\'s experiment what will happen?
  • Fringe will appear for a moment then it will disappear
  • Fringes will occur as from monochromatic light
  • Only bright fringes will appear
  • No fringes will appear
When a thin metal plate is placed in the path of one of the interfering beams of light
  • Fringe width increases
  • Fringes disappear
  • Fringes become brighter
  • Fringes becomes blurred
In Young\'s experiment, the distance between slits is 0.28 mm and distance between slits and screen is 1.4 m. Distance between central bright fringe and third bright fringe is 0.9 cm. What is the wavelength of used light?
  • 5000 Å
  • 6000 Å
  • 7000 Å
  • 9000 Å
Two parallel slits 0.6 mm apart are illuminated by light source of wavelength 6000 Å. The distance between two consecutive dark fringes on a screen lm away from the slits is
  • 1 mm
  • 0.01 mm
  • 0.1 m
  • 10 m
A narrow slit of width 2 mm is illuminated by monochromatic light of wavelength 500 nm. The distance between the first minima on either side on a screen at a distance of lm is
  • 5 mm
  • 0.5 mm
  • 1 mm
  • 10 mm
If a transparent medium of refractive index µ = 1.5 and thickness t = 2.5 × 10–5 m is inserted in front one of the slits of Young\'s Double Slit experiment, how much will be the shift in the interference pattern? The distance between the slit is 0.5 mm and that between slits and screen is 100 cm
  • 5 cm
  • 2.5 cm
  • 0.25 cm
  • 0.1 cm
In a double slit experiment, instead of taking slits of equal widths, one slit is made twice as wide as the other. Then in the interference pattern
  • The intensities of both the maxima and the minima increase
  • The intensity of maxima increases and the minima has zero intensity
  • The intensity of maxima decreases and that of the minima increases
  • The intensity of maxima decreases and the minima has zero intensity
In the Young\'s double slit experiment, for which colour the fringe width is least?
  • Red
  • Green
  • Blue
  • Yellow
In a Young\'s double slit experiment, the separation of the two slits is doubled. To keep the same spacing of fringes, the distance D of the screen from the slits should be made

  • Physics-Wave Optics-95531.png
  • 2)
    Physics-Wave Optics-95532.png
  • 2D
  • 4D
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 through the same point. This is due to
  • 90° change of phase in one of the reflected waves
  • 180° change of phase in one of the reflected waves
  • 145° change of phase in one of the reflected waves
  • 45° change of phase in one of the reflected waves
An interference pattern was made by using red light. If the red light changes with blue light, the fringes will become
  • Wider
  • Narrower
  • Fainter
  • Brighter
If a white light is used in Young\'s double slit experiments then a very large number of coloured fringes can be seen
  • With first order violet fringes being closer to the central white fringes
  • First order red fringes being closer to the central white fringes
  • With a central white fringe
  • With a central black fringe
In Young\'s double slit experiment, the central bright fringe can be identified
  • By using white light instead of monochromatic light
  • As it is narrower than other bright fringes
  • As it is wider than other bright fringes
  • As if has greater intensity than the other bright fringes
In Young\'s double slit experiment, the wavelength of the light used is doubled and distance between two slits is half of initial distance, the resultant fringe width becomes
  • 1/2 times
  • 2 times
  • 3 times
  • 4 times
In a Young\'s double slit experiment, the source illuminating the slits is changed from blue to violet. The width of the fringes
  • Increases
  • Decreases
  • Becomes unequal
  • Remains constant
In Young\'s double slit experiment, the intensity of light coming from the first slit is double the intensity from the second slit. The ratio of the maximum intensity to the minimum intensity on the interference fringe pattern observed is
  • 34
  • 40
  • 25
  • 38
In Young\'s double slit experiment the wavelength of light was changed from 7000 Å to 3500 Å. While doubling the separation between the slits which of the following is not true for this experiment
  • The width of the fringes changes
  • The colour of bright fringes changes
  • The separation between successive bright fringes changes
  • The separation between successive dark fringes remains unchanged
In a Young\'s double slit experiment, the slit separation is 1 mm and the screen is lm from the slit. For a monochromatic light of wavelength 500 nm, the distance of 3rd minima from the central maxima is
  • 0.50 mm
  • 1.25 mm
  • 1.50 mm
  • 1.75 mm
In Young\'s double-slit experiment the fringe width is β. If entire arrangement is placed in a liquid of refractive index n, the fringe width becomes

  • Physics-Wave Optics-95540.png
  • 2)
    Physics-Wave Optics-95541.png

  • Physics-Wave Optics-95542.png

  • Physics-Wave Optics-95543.png
In which of the following is the interference due to the division of wave front?
  • Young's double slit experiment
  • Fresnel's biprism experiment
  • Lloyd's mirror experiment
  • Demonstration colours of thin film
If the separation between slits in Young\'s double slit experiment is reduced to 1/3 rd, the fringe width becomes n times. The value of n is
  • 3
  • 2)
    Physics-Wave Optics-95545.png
  • 9

  • Physics-Wave Optics-95546.png
In an experiment of Newton\'s rings, the diameter of the 20th dark ring was found to be 5.82 mm and that of the 10th ring 3.36 mm. If the radius of the plano-convex lens is 1 m, the wavelength of light used is
  • 5646 Å
  • 5896 Å
  • 5406 Å
  • 5900 Å
The two slits at a distance of 1 mm are illuminated by the light of wavelength 6.5 × 10–7 m. The interference fringes are observed on a screed placed at a distance of lm. The distance between third dark fringe and fifth bright fringe will be
  • 0.65 mm
  • 1.63 mm
  • 3.25 mm
  • 4.88 mm
Two coherent sources of intensity ratio 1 : 4 produce an interference pattern. The fringe visibility will be
  • 1
  • 0.8
  • 0.4
  • 0.6
In Young\'s double slit experiment, distance between two sources 0.1 mm. The distance of screen from the sources is 20 cm. Wavelength of light used is 5460 Å. Then angular position of the first dark fringe is
  • 0.08°
  • 0.16°
  • 0.20°
  • 0.313°
0:0:1


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