Cadet Competition Written Practice Exam

Which term describes heat energy emitted from the sun that has both positive and negative effects?

1. Conduction

2. Radiation

3. Convection

4. Absorption

The correct answer is: Radiation

The term that accurately describes heat energy emitted from the sun is radiation. This process involves the transfer of energy through electromagnetic waves, allowing sunlight to travel through the vacuum of space and reach the Earth. Radiation has both positive and negative effects; for instance, it is essential for life on Earth as it provides the energy necessary for photosynthesis, contributes to the warmth of the planet, and influences weather patterns. However, excessive exposure to solar radiation can lead to negative consequences such as skin damage, increased risk of skin cancer, and other health issues. The other terms do not accurately embody this duality in the context of solar energy. Conduction refers to the transfer of heat through direct contact between materials, which does not apply to how solar energy reaches the Earth. Convection involves the movement of heat through fluids (liquids or gases) and is not the primary mechanism by which solar energy is transmitted. Absorption deals with how materials take in energy rather than the emission aspect related to sunlight itself. Therefore, radiation is the most appropriate term to describe heat energy from the sun, showcasing both its beneficial and detrimental effects.