What is the method of heat transfer that involves infra-red waves positioned above or below food?

Radiant heat is the method of heat transfer that utilizes infra-red waves to cook food by directly transferring energy through radiation. This process does not require a medium such as air or water, allowing heat to be transferred effectively even in a vacuum. Examples of radiant heat include broiling, grilling, or using an oven's broiler, where the heat source, such as heating elements or flames, emits infrared radiation which cooks the food.

Conduction involves direct contact between materials, with heat transferring from one solid object to another. Convection requires a fluid (liquid or gas) to transfer heat, circulating the warmer substance and allowing for even cooking throughout the food. Indirect heat refers to cooking techniques where food is positioned away from the direct source of heat, indirectly warming it. Each of these methods serves a distinct role in cooking, but radiant heat uniquely operates through radiation, making it the correct answer in this context.