⚛️ Physics · Ray Optics and Optical Instruments · NEET & JEE

The refractive index of a transparent medium is 1.5. The speed of light in that medium is:

Answer: 2 10 8 m/s.

A 3 × 108 m/s
B 2 × 108 m/s
C 1.5 × 108 m/s
D 4.5 × 108 m/s

Correct answer: B. 2 × 108 m/s

Explanation: v = c/n = (3 × 108)/1.5 = 2 × 108 m/s.

Concave mirror ray diagram with an object drawn as a candle on the principal axis, the focal point F marked, and the parallel ray and focal ray reflecting to form an inverted real image

Concave mirror ray construction: a ray parallel to the axis reflects through F, and a ray through F reflects parallel, locating the inverted real image. Image: Maxmath12, CC0, via Wikimedia Commons.

Concept context

Reflection, refraction, lenses, mirrors, total internal reflection.

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The refractive index of a transparent medium is 1.5. The speed of light in that medium is:

Concept context

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