Which best describes monochromatic light?

Monochromatic light is defined as light that consists of a single frequency. This means that it has a specific wavelength, which leads to a specific color in the visible spectrum. When light is monochromatic, it does not contain a mixture of different wavelengths, allowing it to maintain a consistent phase relationship across all points in the wavefront.

This single-frequency property makes monochromatic light crucial in many applications, including lasers, where the light produced is focused, easily manipulated, and has minimal dispersion. Other light sources like white light or light from an incandescent bulb consist of multiple frequencies and wavelengths, which leads to a mixture of colors and does not exhibit the same coherence properties as monochromatic light.

Choosing this option accurately describes the nature of monochromatic light, distinguishing it from light that combines varying frequencies or wavelengths, which produce a spectrum of colors instead of a single color effect.