Which phenomenon occurs when light waves change direction after passing through a narrow opening?

• A. Reflection
• B. Diffraction
• C. Refraction
• D. Interference

Answer: (B)

The phenomenon that occurs when light waves change direction after passing through a narrow opening is known as diffraction. This effect arises when waves encounter an obstacle or a slit that is comparable in size to their wavelength. As the light waves pass through the narrow opening, they spread out and bend, creating a pattern of light and dark fringes.

Diffraction is a fundamental behavior of waves, including light, and is particularly notable when the size of the opening is similar to the wavelength of the light. This contrasts with other phenomena, such as reflection, where light bounces off a surface; refraction, which involves the bending of light as it passes through different media; and interference, which is the result of overlapping waves creating patterns of constructive and destructive interference. These distinct behaviors highlight the unique nature of light as a wave, showcasing its ability to bend and spread under certain conditions.