Final answer:
The primary purpose of the layers in electroluminescent lamps is to control light emission, using fluorescent materials to tailor the visible spectrum of light emitted and improve the efficiency of energy conversion from electrical to visible light.
Step-by-step explanation:
The primary purpose of the layers used in the manufacture of electroluminescent lamps is to control light emission. These layers function to manage the conversion of electric energy to visible light. In modern lighting technologies such as LEDs and fluorescent lamps, energy levels of electrons within atoms and crystals are manipulated to produce the desired light. Additionally, materials like fluorescent dyes and phosphorescent substances can transform nonvisible electromagnetic radiation into visible light, enhancing efficiency and allowing for the creation of various color spectrums. Fluorescent materials coating the inside of these lamps play a critical role in converting electrical discharge into a visible and broad spectrum of wavelengths, which can be tailored to resemble sunlight or warm artificial lighting.
By adjusting the features of the fluorescent coatings and the physical design of the lamp layers, manufacturers can refine the light for specific applications, influencing factors such as color temperature and brightness. In the context of the layers' functions, options a, b, and c (to enhance conductivity, reduce energy loss, and increase resistance) are related to the electrical properties of the layers but are not the primary purpose, which focuses on the light-emitting capability of the lamp.