The amplitude and wavelength of light are determined by its characteristics as an electromagnetic wave.
Amplitude: The amplitude of a light wave represents the maximum displacement or intensity of the electric and magnetic fields that make up the wave. In simpler terms, it refers to the brightness or intensity of the light. The higher the amplitude, the brighter the light. The amplitude of light can be adjusted by varying the intensity of the light source.
Wavelength: The wavelength of light refers to the distance between two successive peaks or troughs of the wave. It determines the color or frequency of the light. Light with shorter wavelengths has higher frequencies and appears bluer, while light with longer wavelengths has lower frequencies and appears redder. The wavelength of light is typically measured in nanometers (nm) or meters (m).
The relationship between the wavelength (λ) and frequency (f) of light is given by the equation:
c = λf
where c is the speed of light in a vacuum (~3 × 10^8 meters per second). This equation shows that as the wavelength increases, the frequency decreases, and vice versa.
It's important to note that the amplitude and wavelength of light can affect various aspects of its interaction with matter, including its intensity, color perception, diffraction, interference, and more.