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What is the essential condition for Fraunhofer diffraction?

Important Questions on Wave Optics

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Physics>Optics>Wave Optics>Diffraction
Visible light of wavelength 6000×10-8cm falls normally on a single slit and produces a diffraction pattern. It is found that the second diffraction minimum is at 60o from the central maximum. If the first minimum is produced at θ1, then θ1 is close to
MEDIUM
Physics>Optics>Wave Optics>Diffraction
A single slit of width 0.1 mm is illuminated by a parallel beam of light of wavelength 6000 Å and diffraction bands are observed on a screen 0.5 m from the slit. The distance of the third dark band from the central bright band is:
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Physics>Optics>Wave Optics>Diffraction
A beam of light of λ=600 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2 m away. The distance between first dark fringes on either side of the central bright fringe is:
HARD
Physics>Optics>Wave Optics>Diffraction
A screen is placed 2 m away from a narrow slit. If the first minimum lies 5 mm from either side of the central maxima, when plane waves of wave length 5×10-7 m are used, the slit width is:
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Physics>Optics>Wave Optics>Diffraction
A parallel beam of electrons travelling in x - direction falls on a slit of width d (see figure). If after passing the slit, an electron acquires momentum py in the y - direction then for a majority of electrons passing through the slit (h is Planck's constant):

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EASY
Physics>Optics>Wave Optics>Diffraction
A Fraunhofer diffraction pattern due to a single slit of width 0.3 mm is obtained on a screen placed at a distance of 3 m from the slit. The first minima lie at 5.5 mm on either side of the central maximum on the screen. The wavelength of light used is
MEDIUM
Physics>Optics>Wave Optics>Diffraction
The angular width of the central maximum in a single slit diffraction pattern is 60° . The width of the slit is 1 μm. The slit is illuminated by monochromatic plane waves. If another slit of the same width is made near it, Young's fringes can be observed on a screen placed at a distance 50 cm from the slits. If the observed fringe width is 1 cm, what is slit separation distance? (i.e., the distance between the centres of each slit.)
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Physics>Optics>Wave Optics>Diffraction
A screen is placed 50 cm from a single slit, which is illuminated with a light of wavelength 600 nm. If the distance between the first and third maxima in the diffraction pattern is 3 mm. then calculate its slit width.
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Physics>Optics>Wave Optics>Diffraction
A linear aperture whose width is 0.02 cm is placed immediately in front of a lens of focal length 60 cm. The aperture is illuminated normally by a parallel beam of wavelength 5×10-5 cm. The distance of the first dark band of the diffraction pattern from the centre of the screen is
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Physics>Optics>Wave Optics>Diffraction
A parallel beam of light of wavelength 4000 A∘ passes through a slit of width 5×10-3 m. The angular spread of the central maxima in the diffraction pattern is
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Physics>Optics>Wave Optics>Diffraction
Consider the diffraction pattern obtained from the sunlight incident on a pinhole of diameter 0.1 μm. If the diameter of the pinhole is slightly increased, it will affect the diffraction pattern such that
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Physics>Optics>Wave Optics>Diffraction
At the first minimum adjacent to the central maximum of a single-slit diffraction pattern, the phase difference between the Huygen's wavelet from the edge of the slit and the wavelet from the midpoint of the slit is:
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Physics>Optics>Wave Optics>Diffraction
In a single slit diffraction (of width α) by a monochromatic source of wavelength λ the first minimum of the intensity distribution occurs at an angle
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Physics>Optics>Wave Optics>Diffraction
Orange light of wavelength  6000×10–10 m illuminates a single slit of width 0.6×10–4 m. The maximum possible number of diffraction minima produced on both sides of the central maximum is __________
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Physics>Optics>Wave Optics>Diffraction
Which of the statements are correct with reference to single slit diffraction pattern?
(i) Fringes are of unequal width
(ii) Fringes are of equal width
(iii) Light energy is conserved
(iv) Intensities of all bright fringes are equal
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Physics>Optics>Wave Optics>Diffraction
In the diffraction due to a single slit experiment, the aperture of the slit is 3 mm. If monochromatic light of wavelength 620 nm is incident normally on the slit, calculate the separation between the first order minima and the 3rd order maxima on one side of the screen. The distance between the slit and the screen is 1.5 m.
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Physics>Optics>Wave Optics>Diffraction
A screen is placed 50 cm from a single slit which is illuminated with light of wavelength 600 nm. If the distance between the first and third minima is the diffraction pattem is 3 mm. the width of the slit is.
MEDIUM
Physics>Optics>Wave Optics>Diffraction
A single slit of width b is illuminated by a coherent monochromatic light of wavelength λ. If the second and fourth minima in the diffraction pattern at a distance 1 cm from the slit are at 3 cm and 6 cm respectively from the central maximum, what is the width of the central maximum? (i.e. distance between first minimum on either side of the central maximum)
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Physics>Optics>Wave Optics>Diffraction
For a parallel beam of monochromatic light of wavelength λ, diffraction is produced by a single slit whose width a is of the order of the wavelength of the light. If D is the distance of the screen from the slit, the width of the central maxima will be:
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Physics>Optics>Wave Optics>Diffraction
In a diffraction pattern due to a single slit of width a the first minimum is observed at an angle 30o when light of wavelength 5000 Å is incident on the slit. The first secondary maximum is observed at an angle of: