CBSE Class 10 Answered

The quantum theory of light is way above the scope of this help desk. However you can understand the concepts as, in interference, the two light waves super-impose over one another. And in diffraction, the light waves traveling interact with any object of size comparable to the wavelength of the light wave then it exchanges energy to that object and we say the wave to be diffracted or scattered. In polarization, we restrict the vibrating components of electric and magnetic field in a light wave. these phenomenons can be explained by wave theory of light because in them we have to consider the wave mechanics. Whereas in some phenomenons like photoelectric effect, we have to consider the particle nature. Actually all these particles called photons are not real particles they are just hypothesized to make mathematics easier as in quantum world we can only have discreet levels of energy which are taken as energy of these particles. Thus in phenomenons involving quantum mechanics we have to apply particle nature and in classical the wave nature is used.