Physics
What is a total reflecting prism? State three actions that it can produce. Draw a diagram to show one such action of the total reflecting prism.
Refraction Plane Surfaces
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Answer
A prism having an angle of 90° between its two refracting surfaces and the other two angles each equal to 45° is called a total reflecting prism. In such a prism, the light incident normally on any of its faces suffers total internal reflection inside the prism.
Due to this property, a total reflecting prism is used for the following three purposes —
- To deviate a ray of light through 90°.
- To deviate a ray of light through 180°.
- To erect the inverted image without producing deviation in its path.
Below diagram shows the deviation of a ray of light through 90° by a total reflecting prism:
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