Diffraction Due to Single Slit
Diffraction is supposed to be due to interference of secondary wavelets from the exposed portion of the wavefront from the slit. Whereas in interference, all bright fringes have the same intensity. In diffraction, bright bands are of decreasing intensity.
Condition for minimum intensity is given by,
a sin θ = nλ (n = 1, 2, 3, …..)
where,
- a is the width of the slit
- θ is the angle of diffraction
Condition for maximum intensity is given by,
a sinθ = (2n + 1) λ/2 (n = 1, 2, 3, ….)
where,
- a is the width of the slit
- θ is the angle of diffraction.
Problems on Diffraction – Class 12 Physics
The bending of light at the edges of an obstacle whose size is comparable to the wavelength of light is called diffraction. To put it another way, it is the spreading of waves when they go through or around a barrier. Diffraction of light, as it is used to describe light, occurs more explicitly when a light wave passes by a corner or via an opening or slit that is physically smaller than the wavelength of that light, if not even smaller. The ratio of the wavelength of the light to the opening size determines how much bending occurs. The bending will essentially be undetectable if the aperture is substantially greater than the light’s wavelength. However, if the two are of similar size or are equal in size, there is a noticeable degree of bending that can be observed with the unaided eye.
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