A black metal solar panel and a white ceramic tile are expos - HiSET Prep

Correct Answer: B. The black color and metallic surface of the panel promote heat absorption and efficient conduction. Black surfaces have high absorptivity across the solar spectrum; they take in more incident sunlight than white or reflective surfaces. A metal solar panel combines high absorptivity (black coating) with high thermal conductivity, so absorbed energy is rapidly converted into internal energy and distributed through the panel, raising its temperature quickly. Metals also often have relatively low volumetric specific heat (per unit surface area) compared to dense ceramics in practical panel geometries, so for the same absorbed energy the metal’s surface temperature can rise more. In short: black color increases absorbed power; metallic conduction spreads and concentrates that energy efficiently; both contribute to the panel becoming much hotter than a reflective or white ceramic tile under identical illumination.

Why the Other Options Are Incorrect:

• A. The metal’s low density and smooth surface cause greater reflection of solar radiation.
  Low density and smoothness do not logically lead to greater absorption; smooth metallic surfaces tend to reflect, not absorb. Also, many metals are dense. The panel’s high temperature is due to absorption, not reflection. A highly reflective surface would heat less, not more.

• C. The white tile absorbs more heat but stores less due to low specific heat capacity.
  White surfaces reflect a large portion of incident sunlight, so they absorb less, not more. Ceramic tiles often have higher specific heat than thin metal panels, so they can store more energy without large temperature increases. The premise that the white tile absorbs more is incorrect.

• D. The ceramic tile conducts heat more efficiently, so less heat remains on its surface.
  Most ceramics are poor conductors (low thermal conductivity) compared with metals; they tend to remain closer to the point of absorption and can conduct heat slowly into the bulk. The observed higher surface temperature of the metal panel is not because the ceramic conducts better; it’s because the metal both absorbs more (black) and conducts the absorbed energy fast enough to raise its temperature and equalize it across the surface.