Associate Safety Professional Practice Exam

When white light passes through a triangular prism, which color is refracted the least?

1. Green

2. Blue

3. Red

4. Violet

The correct answer is: Red

When white light passes through a triangular prism, different colors of light are refracted by different amounts due to their varying wavelengths. Refraction occurs because light travels at different speeds in different mediums, and this speed changes depending on the color or wavelength of the light. Red light has the longest wavelength of the visible spectrum, which means it is refracted the least when passing through a prism. The bending of light is more pronounced for shorter wavelengths, such as blue and violet, which have shorter wavelengths and are refracted more. Therefore, since red light is at the opposite end of the spectrum with the longest wavelength, it experiences the least amount of bending, making it the color that is refracted the least when passing through the prism. This property of light behavior is fundamental in optics and is part of the phenomenon known as dispersion, which is responsible for the formation of rainbows and the separation of colors in a prism.