In an oven, heat is generated by one or more heating elements, typically located at the bottom or top of the oven cavity. These heating elements convert electrical energy into heat energy through electrical resistance, producing high temperatures within the oven.
When the oven is turned on and set to a specific temperature, the heating elements start to generate heat. The heat energy is then transferred to the surrounding air within the oven through a process called convection. Convection is the transfer of heat through the movement of hot air or fluid particles.
As the heating elements warm up, the air in the oven cavity closest to the elements becomes hot. Hot air is less dense than cold air, so it rises and creates a natural circulation pattern within the oven. This rising hot air is replaced by cooler air, creating a convection current. The movement of this hot air throughout the oven helps distribute the heat evenly, ensuring that the food is cooked uniformly.
In addition to convection, heat is also transferred to the food through radiation. The hot surfaces inside the oven, such as the walls and racks, emit thermal radiation. This radiant heat travels in straight lines and directly heats the food, especially the surfaces that are exposed to the direct line of sight with the hot surfaces.
The combination of convection and radiation is responsible for heating the food inside the oven. The food absorbs the radiant heat and is surrounded by the hot air, which cooks it from all sides. The heating process continues until the desired temperature is reached, or until the oven is turned off.
It's worth noting that some ovens also have a broil function, which primarily uses radiant heat from the top heating element to cook the food. This is particularly useful for browning the top of dishes or creating a crust.
Overall, the heat generated by the oven is transferred to the food through convection and radiation, ensuring that the food is cooked thoroughly and evenly.