Question

When total internal reflection occurs from a prism,________of incident light is reflected back to denser medium. Fill on the blank.

• A. 50%
• B. 100%
• C. 20%
• D. 70%

Answer 1

Answer: (B)

100%

Answer: B option

When light enters in glass from air, it likes to reflect back by wave front theory (although 1-2%). In case of from denser to rarer medium first below critical angle some part of it is reflected back and some is refracted, but above critical angle some is reflected and other part (which was earlier refracted) is even reflected back causing 100% reflection back.