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Question
Discuss about pile of plates.
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Solution
- The phenomenon of polarisation by reflection is used in the construction of pile of plates.
- It consists of a number of glass plates placed one over the other in a tube
- The plates are inclined at an angle of 33.7°(90° – 56.3°) to the axis of the tube. A beam of unpolarised light is allowed to fall on the pile of plates along the axis of the tube. So, the angle of incidence of light will be at 56.3° which is the polarising angle for glass.
Pile of plates - The vibrations perpendicular to the plane of incidence are reflected at each surface and those parallel to it are transmitted.
- The larger the number of surfaces, the greater is the intensity of the reflected plane polarised light.
- The pile of plates is used as a polarizer and also as an analyser.
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