Answer :
The width (in mm) of the central maximum on a screen 1.4 m behind the slit = 0.014 mm.
Diffraction of light
Diffraction of light on a single slit will produce maximum interference from the slit if the path difference between the light coming is:
(2n+1) Ā½ Ī»
Maximum interference if the difference in the paths taken by light from adjacent slits is equal to an integer multiple times the wavelength or also an even number times the half wave.
To determine the width from the maximum center on the screen behind the slit. use the equation:
Ym = mĪ»D/a
We have,
a = 190 Ī»
So,
Yā = (1)Ī» (1.4) / 190 Ī»
= 0.007 m
And, width of the central maximum can be determined as:
Wc = 2Yā
= 2 (0.007)
= 0.014 mm
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