A ray of light is incident normally on one of the refracting surfaces of a prism of refracting angle A. The emergent ray grazes the other refracting surface. Find the refractive index of the material of the prism.

A ray of light is incident normally on one of the refracting surfaces

1.	A ray of light is incident normally on one of the refracting surfaces of a prism of refracting angle A. The emergent ray grazes the other refracting surface. Find the refractive index of the material of the prism.
Answer» <html><body><p></p><a href="https://interviewquestions.tuteehub.com/tag/solution-25781" style="font-weight:bold;" target="_blank" title="Click to know more about SOLUTION">SOLUTION</a> :For normal <a href="https://interviewquestions.tuteehub.com/tag/incidence-1039767" style="font-weight:bold;" target="_blank" title="Click to know more about INCIDENCE">INCIDENCE</a> on <a href="https://interviewquestions.tuteehub.com/tag/one-585732" style="font-weight:bold;" target="_blank" title="Click to know more about ONE">ONE</a> of the refracting faces of the prism `i_1=0 and r_1=0` But `r_1+r_2=A` when light undergoes refraction through a <a href="https://interviewquestions.tuteehub.com/tag/prisms-1166635" style="font-weight:bold;" target="_blank" title="Click to know more about PRISMS">PRISMS</a>. <br/> `therefore 0+r_2=A, r_2=A` <br/> When the emergent light grazes the second surface, `r_2` becomes the critical angle ( <a href="https://interviewquestions.tuteehub.com/tag/c-7168" style="font-weight:bold;" target="_blank" title="Click to know more about C">C</a>) <br/> i.e., `C=A and mu=1/(sin C)=1/ (sin A)`</body></html>