Answer :
In the given problem, we are asked how heat transfer can occur between two bodies separated in a vacuum. Let's go through the thermodynamic concepts involved in heat transfer:
Convection: This is the transfer of heat through a fluid (liquid or gas) moving from one place to another. Convection cannot occur in a vacuum because there are no particles to move and carry the heat energy. Therefore, convection does not apply to the situation described.
Conduction: This type of heat transfer occurs when heat moves through a solid or between solids in direct contact. In a vacuum, there are no materials or particles to facilitate conductive heat transfer, so conduction does not occur in a vacuum.
Radiation: This is the transfer of heat in the form of electromagnetic waves, such as infrared waves, that can travel through a vacuum. Radiation is the only mode of heat transfer that can occur between two bodies separated by a vacuum because it does not require a medium (solid, liquid, or gas) to transfer energy.
Based on the explanation above, the correct answer to the question is: radiation. Heat transfer between two bodies in a vacuum occurs through radiation.
