Lesson: Total Internal Reflection Physics • 9th Grade

In this lesson, we will learn how to define total internal reflection (TIR) by describing rays produced by light rays incident at or past the critical angle for TIR.

Lesson Plan

Students will be able to

recognize that light incident on a media boundary can be totally internally reflected if the light propagates in a medium of greater refractive index than on the other side of the boundary,
recognize that only light rays incident at angles greater than the critical angle are totally internally reflected.

Lesson Video

Lesson Explainer

Sample Question Videos

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Lesson Worksheet

Q1:

The rays A, B, and C are shown incident on a boundary between water and air, traveling in water. Which incident ray produces total internal reflection?

Q2:

Which of the following definitions best describes the critical angle for total internal reflection?

Q3:

Which of the following sets of conditions best describes total internal reflection?