Refraction Of Light Video Lessons

Concept

Problem: A ray of light is incident in air on a block of a transparent solid whose index of refraction is n. If n = 1.34, what is the largest angle of incidence for which total internal reflection will occur at the vertical face (point shown in the figure )?

FREE Expert Solution

The critical angle is expressed as:

$\overline{){{\mathbf{\theta }}}_{{\mathbf{c}}}{\mathbf{=}}{\mathbf{s}}{\mathbf{i}}{{\mathbf{n}}}^{\mathbf{-}\mathbf{1}}{\mathbf{\left(}}\frac{{\mathbf{\eta }}_{\mathbf{a}}}{{\mathbf{\eta }}_{\mathbf{c}}}{\mathbf{\right)}}}$

Snell's law:

$\overline{){{\mathbf{\eta }}}_{{\mathbf{1}}}{\mathbf{s}}{\mathbf{i}}{\mathbf{n}}{{\mathbf{\theta }}}_{{\mathbf{1}}}{\mathbf{=}}{{\mathbf{\eta }}}_{{\mathbf{2}}}{\mathbf{s}}{\mathbf{i}}{\mathbf{n}}{{\mathbf{\theta }}}_{{\mathbf{2}}}}$

This can be expressed in the diagram below;

θc = sin-1(1/1.34) = 48.2°

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Problem Details

A ray of light is incident in air on a block of a transparent solid whose index of refraction is n. If n = 1.34, what is the largest angle of incidence for which total internal reflection will occur at the vertical face (point shown in the figure )?