State the Principle of reversibility of light
The principle that if a beam of light is reflected back on itself, it will traverse the same path or paths as it did before reversal.
The principle of reversibility states that light will follow exactly the same path if its direction of travel is reversed.
Using Snell's Law,
It follows that
The principle of reversibility of light states that light follows the same path if the direction of the travel of light is reversed. In its simplest explanation, the principle of reversibility is a deduction of Snell's law of the refraction of light.
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