Physics Wave Optics

Yes, both coherent and incoherent waves can be seen by the naked eye. However, we cannot detect whether the wave is coherent or incoherent. This is because the incoherent waves have different frequencies which cannot be distinguished by the human eye. We have can only see lights of specific wavelengths as per the human limit.

Yes, whether a wave is coherent or incoherent depends on its phase difference and frequency. For converting a coherent wave into an incoherent wave, you have to damage the stable phase of the wave. This can be done by making the medium tough or mixing them with incoherent waves.

Similarly, incoherent waves can be converted into coherent waves by making their frequencies same and having all of them into the same phase.

Yes, it strongly depends on the wavelength of the light wave. It is directly proportional to the length i.e. longer the wavelength, more will be the amount of diffraction. Similarly, short wavelength of the light will mean less diffraction comparatively.

Reflection is the concept of bouncing back of light waves when passed through a surface. Whereas, diffraction is a term used when light waves spread in different directions on being passed through an obstacle. Reflection requires a smooth surface whereas diffraction requires the edge of an object.

Interference is a concept that forms the base of diffraction, without which diffraction is not practically possible. The waves formed by diffraction form secondary waves which either cross each other, move in directions opposite to each other, or overlap each other. This situation creates some alternating bright and dark fringes called interference.

qR =1/60º for human eye

⇒x = 21.6 km

For minima

$d\cos ?\theta =\left(n+\frac{1}{2}\right)\lambda$

$?\cos ?\theta =\frac{2n+1}{8}$

$?n=-4,-3,-2,-1,0,1,2,3$

$?8$

minimas

Please find the answer below

Interference is the result of the superposition of waves.

For minima

$d\cos ?\theta =\left(n+\frac{1}{2}\right)\lambda$

$?\cos ?\theta =\frac{2n+1}{8}$

$?n=-4,-3,-2,-1,0,1,2,3$

$?8$ minimas