An Optic Fiber Is Made of Clear Plastic with an Index

question 156

Multiple Choice

An optic fiber is made of clear plastic with an index of refraction of $1.50$ . For what range of angles of incidence $\theta$ with the lateral surface of the fiber will light remain inside the plastic "guide" if it is surrounded by air?

• A) \(23.4 ^ { \circ } < \theta < 90 ^ { \circ }\)
• B) \(41.8 ^ { \circ } < \theta < 90 ^ { \circ }\)
• C) \(38.3 ^ { \circ } < \theta < 90 ^ { \circ }\)
• D) \(21.1 ^ { \circ } < \theta < 90 ^ { \circ }\)
• E) \(40.3 ^ { \circ } < \theta < 90 ^ { \circ }\)

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Definitions:

Acres

A unit of land area measurement used in the U.S. customary and imperial systems, equal to 43,560 square feet or about 4,047 square meters.

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A cereal grain that is a staple food worldwide, used for making products like bread, pasta, and flour.

Barley

A cereal grain that is used in various foods, beverages, and as animal feed.