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

A person sees a fish that appears 12 cm deep in water (n=1.33). Actual depth of fish:

Answer: 16 cm.

A 9 cm
B 12 cm
C 16 cm
D 24 cm

Correct answer: C. 16 cm

Explanation: Apparent depth = real depth/n. 12 = real depth/1.33. Real depth = 12 x 1.33 = 16 cm.

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 person sees a fish that appears 12 cm deep in water (n=1.33). Actual depth of fish:

Concept context

More Ray Optics and Optical Instruments questions