Question

When does the light ray incident on a rectangular glass slab immersed in any medium emerge parallel to itself

Answer 1

So it deviates away from normal. Since, the glass slab is rectangular and both sides of the glass slab have the same medium. The light refracts in such a way that incident and emergent rays are parallel

Answer 2

Explanation:

When ray of light incident on a rectangular glass slab emergent ray is parallel to the direction of incident ray.

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