why angle of incidence=angle of reflected ray

Asked by  | 20th Oct, 2010, 04:35: PM

Expert Answer:

Dear Student
The equality of angle of incidence to angle of reflection follows from the Fermat's principle of least time. According to the principle , the path actually taken by a ray of light in passing from one point to another is the path of least time.

Fermat's Principle: Light follows the path of least time. The law of reflection can be derived from this principle as follows:

The pathlength L from A to B is

Since the speed is constant, the minimum time path is simply the minimum distance path. This may be found by setting the derivative of L with respect to x equal to zero.


Hope that satisfies your query.

Answered by  | 20th Oct, 2010, 06:31: PM

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