Interference and Diffraction Bands
If N interference bands are contained by the width of the central bright, then the width of the band becomes equal to Nβ or N(Dλ/d). Therefore the width of the slit is expressed as,
a = 2d/N
where,
- a is the width of the slit
- d is the diffraction value
- N is the number of bands
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.