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SCIENCES PHYSIQUES ET CHIMIQUES – ANGLAIS
Diffraction
Task: do the following exercise
Light issued from a laser is diffracted by a slit of width 0.10 mm. The obtained pattern is observed
on a screen located at 2.0 m from the slit, and its central spot is 2.1 cm wide.
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What phenomenon occurred?
Draw a sketch of the device. Comment on what happens.
Give the angular deviation between the extreme rays forming the central spot.
Find the wavelength of the radiation emitted by the laser.
Calculate its frequency.
With the same device, a red laser source of wavelength 670 nm is used. How is the pattern
modified?
Celerity of light in vacuum: 3.00 x 108 m.s-1
ANG PHYOND 116099544
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