Ham Radio General Class Practice Test

What feature allows a photovoltaic cell to produce electricity?

1. The absorption of sunlight

2. The reflection of sunlight

3. The increase in temperature caused by sunlight

4. The alignment of silicon atoms

The correct answer is: The absorption of sunlight

A photovoltaic cell generates electricity primarily due to the absorption of sunlight. When sunlight strikes the surface of the photovoltaic cell, it is composed of semiconductor materials, usually silicon. This absorbed energy from the sunlight excites electrons in the semiconductor, allowing them to move freely. As these electrons move, they create an electric current. While reflection and temperature are related to how solar cells function, they do not directly contribute to electricity generation in the same way that absorption does. Reflection can actually decrease the efficiency of a solar panel as it suggests that not all of the incoming sunlight is being utilized. Similarly, while the heat generated by sunlight can affect a solar panel's efficiency, it does not produce electricity. The alignment of silicon atoms is crucial for the functioning of the solar cell as a whole, but it is the absorption of sunlight that initiates the process of converting solar energy into electrical energy. Therefore, it is the absorption that is fundamental to the generation of electricity in photovoltaic cells.