Light That Has Been Traveling in a Medium with an Index

question 56

Multiple Choice

Light that has been traveling in a medium with an index of refraction n₂ is incident on the boundary surface of another medium with an index of refraction n₁.Given a sufficient angle of incidence,which of the following conditions must be satisfied for total internal reflection to occur?

• A)n₁ < n₂
• B)n₁ > n₂
• C)n₁ = n₂
• D)Any of these may be correct.
• E)None of these is correct.

---

Definitions:

Pyroclastic Flow

A fast-moving current of hot gas and volcanic materials (ash, lava fragments) that flows down the sides of a volcano during an explosive eruption.

Lahar

A mudflow mostly composed of volcanic-derived materials and generally formed on the flank of a volcano.

Composite Volcanoes

Volcanoes constructed from multiple layers of lava flows, volcanic ash, and other volcanic debris, characterized by steep profiles and periodic explosive eruptions.

Lahars

Volcanic mudflows or debris flows that occur when volcanic materials become saturated with water and rapidly move down slopes.