HARD
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Draw and compare the intensity graph of single slit diffraction and double slit interference.

Important Questions on Wave Optics

MEDIUM
Physics>Optics>Wave Optics>Diffraction of Light
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
EASY
Physics>Optics>Wave Optics>Diffraction of Light
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:
EASY
Physics>Optics>Wave Optics>Diffraction of Light
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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MEDIUM
Physics>Optics>Wave Optics>Diffraction of Light
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:
EASY
Physics>Optics>Wave Optics>Diffraction of Light
Write any two differences between and interference of light.
MEDIUM
Physics>Optics>Wave Optics>Diffraction of Light
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)
EASY
Physics>Optics>Wave Optics>Diffraction of Light
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:
HARD
Physics>Optics>Wave Optics>Diffraction of Light
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:
MEDIUM
Physics>Optics>Wave Optics>Diffraction of Light
Write four differences between interference and diffraction.
EASY
Physics>Optics>Wave Optics>Diffraction of Light
For what distance is ray optics a good approximation when the aperture is 4 mm wide and the wavelength is 500 nm ?
MEDIUM
Physics>Optics>Wave Optics>Diffraction of Light
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.)
MEDIUM
Physics>Optics>Wave Optics>Diffraction of Light
 Describe any two characteristic features which distinguish between interference and diffraction phenomena. Derive the expression for the intensity at a point of the interference pattern in Young’s double slit experiment.
EASY
Physics>Optics>Wave Optics>Diffraction of Light
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:
EASY
Physics>Optics>Wave Optics>Diffraction of Light
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
HARD
Physics>Optics>Wave Optics>Diffraction of Light
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 of Light
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
EASY
Physics>Optics>Wave Optics>Diffraction of Light
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
EASY
Physics>Optics>Wave Optics>Diffraction of Light
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
MEDIUM
Physics>Optics>Wave Optics>Diffraction of Light
What do you understand by diffraction? Write the difference between diffraction and interference.
EASY
Physics>Optics>Wave Optics>Diffraction of Light
For what distance the ray optics will be a good approximation when the aperture is 5 mm wide and the wavelength is 450 nm?