Written Laser Hair Removal Practice Exam 2026 - Free Laser Hair Removal Practice Questions and Study Guide

Red has the longest wavelength in visible light among the options provided. In the visible light spectrum, red light has the longest wavelength and the lowest frequency, while blue light has the shortest wavelength and the highest frequency. Wavelength and frequency are inversely related - as the wavelength increases, the frequency decreases. Therefore, red light with its longer wavelength is the correct answer in this case.