Which electrical effect involves the interaction of radiation with matter?

The photoelectric effect involves the interaction of light (or radiation) with matter, specifically how photons can eject electrons from a material when the energy of the photons exceeds a certain threshold. This phenomenon demonstrates the particle-like properties of light, where individual light quanta (photons) impact matter, leading to the emission of electrons.

In contrast, the other options do not primarily focus on the interaction of radiation with matter in the same way. A battery operates on chemical reactions to generate electrical energy, not radiation. A photo cell (or photovoltaic cell) converts light into electricity, but its primary function is not to illustrate the direct interaction of radiation and matter as the photoelectric effect does. A thermocouple generates a voltage based on temperature differences, again not directly relating to the interaction of radiation with matter. Thus, the photoelectric effect is distinctly recognized as the phenomenon describing the interaction between light and electrons.