In a scenario where thermal energy is exchanged, what must exist for conduction to be effective?

For conduction to be effective, there must be a temperature gradient present. Conduction involves the transfer of thermal energy through direct contact between materials. When there is a difference in temperature between two regions, heat will naturally flow from the hotter area to the cooler one until thermal equilibrium is reached. This temperature difference, or gradient, drives the movement of thermal energy.

In the absence of a temperature gradient, there would be no driving force for heat transfer. If two materials are at the same temperature, there will be no net flow of heat, and conduction will not occur. Therefore, a temperature gradient is essential for efficient heat transfer through conduction.