Polarisation

Any thing which is normal as per the nature’s requirement is unpolarized. Polarization is the state of a system which is under a force because of an external agency which looks to be more systematic and conditioned compared to the natural state. Is it not right to wonder under the state of polarization the system is under strain!!!? The greatest inference the polarization of light has given is not only that light is a transverse wave, it is an electromagnetic wave.
Different types of polarizations like Circular polarization, Elliptical polarization etc are possible through the combination of plane polarized light which can be achieved through different methods like use of Nicole prism, polaroiders etc.,

de-Broglie’s hypothesis

The experiments on intereference, diffraction and polarization in light infer that light behaves as waves. While the Photoelectric effect infers that the light at the time of interaction show that they behave as quanta( particle) .
The X- rays through the process of diffraction show that they are waves, while the same X-rays show that they are scattered as if they are particles following the law of conservation of energy.
The above two examples clearly talk of duality of electromagnetic radiation.

Mechanics

Classical mechanics and classical physics which are studied to understand the law of nature in terms of what we see and feel about our surroundings is basically depends upon our common sense. The overall performance of all these classical phenomena depends upon the nature of basic constituents of these surroundings that is on atomic and molecular behavior. The phenomena occur at these microstructures do not seems to work on common sense. This is because of the concept of quantization of energy which led to the branch of Quantum Mechanics further which led to the new beginning of Modern Physics.

Thermionic emission.

Why can we see light when we switch on the bulb or tube? Have you ever thought of this? When we switch on a bulb, current flow through the tungsten filament of the bulb. Filament heats up and as a result of this, it emits photons. This is called thermionic emission.