The spectrum of light from a filament lamp is a continuous spectrum of colour from deep violet at about 350nm to deep red at about 650nm. The most intense part of the spectrum depends on the temperature of the light source. The hotter the light source, the shorter the wavelength of the brighest part of the spectrum. By measuring the wavelength of the brightest part of the continuous spectrom, we can therefore measure the temperature of the light source.
Line emission spectra
A glowing gas in a vapour lamp or a discharge tube emits light at specific wavelengths so its spectrum…