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Question
Describe briefly using a diagram how sunlight is polarised ?
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Solution
The incident sunlight is unpolarised. The dot and double arrows show the polarization in the perpendicular and in the plane of the figure. Under the influence of the electric field of the incident wave, the electrons in the molecules of the atmosphere acquire components of motion in both these directions. An observer looking at 90° to the direction of the sun, the charges accelerating parallel to the double arrows do not radiate energy towards this observer since their acceleration has no transverse component. The radiation scattered by the molecule is therefore represented by dots. It is linearly polarized perpendicular to the plane of the figure.
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The following figure shows a cross-section of a ‘light pipe’ made of a glass fiber of refractive index 1.68. The outer covering of the pipe is made of a material of refractive index 1.44. What is the range of the angles of the incident rays with the axis of the pipe for the following phenomena to occur.
