Optics, refraction at spherical surface

AI Thread Summary
The discussion revolves around a homework question regarding the distance of an "unilluminated patch" from a cylindrical surface in optics. The original poster expresses confusion about the question, particularly about the intersection of rays and the concept of illumination. A participant suggests considering the critical angle as a hint to solve the problem. The original poster finds this hint helpful and successfully resolves their confusion. The interaction highlights the importance of understanding critical angles in optics.
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Homework Statement


(see attachment)


Homework Equations





The Attempt at a Solution


I don't quite understand the question. It asks the distance of the "unilluminated patch" from the cylinder. There will be only a single point where the rays will intersect. Rest everywhere, it is unilluminated or am I missing something?

Any help is appreciated. Thanks!
 

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Hi Pranav-Arora! :smile:

Hint: critical angle. :wink:
 
tiny-tim said:
Hi Pranav-Arora! :smile:

Hint: critical angle. :wink:

Thanks a lot tiny-tim! That solved the problem in an instant. :smile:
 

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