A Light Ray Is Partially Reflected and Partially Refracted at a Boundary

question 28

Multiple Choice

A light ray is partially reflected and partially refracted at a boundary between two media,the upper one having index of refraction n,the lower one having index of refraction n',as shown in the figure.The reflected ray is perpendicular to the refracted ray when

• A) .
• B) .
• C) .
• D) .
• E) .