Question : Explain polarization of light.
Answer : According to electromagnetic theory of wave light is a transverse wave.In this wave there are vibrating electric field E=E0 and vibrating magnetic field B=B0 .Both the vectors vibrate perpendicularly with the direction propagation.The plane made by E with the direction of propagation is called the plane of vibration.
A light wave consists of numerous wave trains or pulses.The planes of vibrations of all the pulses are oriented.Such a light wave is called an unpolarized light.If the planes of vibrations of all the pulses are parallel then such a light wave is called a polarized light.
Tourmaline crystal and calcite crystal (CaCO3) each of which has a characteristic direction .All the longest diagonals of the crystal structure are parallel to the characteristic direction called the optic axis.If a crystal is placed in front of an unpolarised light then the pules having E vector parallel to the optic axis pass through it.The planes of vibrations of the transmitted pulses are parallel.It is called a polarized light and the phenomenon is called polarization.The plane of vibrations of the polarized light is called the plane of polarization.The crystal is called a polarizer or polarizing sheet.If a second crystal is placed in front of a polarized light perpendicularly with the plane of polarization no light will be transmitted.The second crystal is called an analyzer.
Question : What is unpolarized light?
Answer : If the planes of vibrations of all the pulses of a light wave are different then the light is called an unpolarised light.
Question : What is polarized light ?
Answer : If the planes of vibrations of all the pulses of a light wave are parallel then the light wave is called a polarized light.
Question :What is polarization of light ?
Answer : If a crystal is placed in front of an unpolarized light the pulses having E vector parallel to the optic axis pass through the crystal.The transmitted light becomes a polarized light.The phenomenol is known as polarization.