Institution: জাতীয় কবি কাজী নজরুল ইসলাম বিশ্ববিদ্যালয় (JKKNIU) Exam: ঙ ইউনিট || জাতীয় কবি কাজী নজরুল ইসলাম বিশ্ববিদ্যালয় || 2012
Topic: Pair of Word, Subject: English Grammar (ইংরেজি গ্রামার)

Best Answer Explained in Below-:

The word "refract" originates from the Latin word "refractus," which means "to break back." In contemporary usage, especially in the fields of physics and optics, "refract" specifically refers to the phenomenon where a wave, such as light or sound, changes direction as it passes from one medium to another—this bending of the wave occurs due to a change in its speed. For example, when light travels from air into water, it slows down and bends, causing objects underwater to appear displaced.

The other options—A) Repeat, C) Split, and D) Reduce—do not capture the essence of the term "refract." While "split" might seem somewhat related if interpreted loosely, it does not convey the precise action of bending. In essence, "to bend" is the most accurate description of what happens during refraction, making B the correct choice. Understanding this meaning is crucial in various practical and scientific contexts, from designing lenses to understanding natural phenomena like rainbows.