A ray enters glass slab at 30 degrees to the normal. n glass = 1.5. Angle of refraction:

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

A ray enters glass slab at 30 degrees to the normal. n<sub>glass</sub> = 1.5. Angle of refraction:

Answer: 19.5 degrees.

A 19.5 degrees
B 30 degrees
C 45 degrees
D 60 degrees

Correct answer: A. 19.5 degrees

Explanation: Snell: 1 x sin30 = 1.5 x sin(r). sin(r) = 0.5/1.5 = 0.333. r = sin<sup>-1</sup>(0.333) = 19.5 degrees.

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.

Read the full Ray Optics and Optical Instruments notes →

A ray enters glass slab at 30 degrees to the normal. n<sub>glass</sub> = 1.5. Angle of refraction:

Concept context

More Ray Optics and Optical Instruments questions