What demonstrates the transfer of heat from the pan to the water?

• A. Heating of water in a pan on a fire
• B. Cooling of water in a freezer
• C. Heating of air in a room
• D. Boiling of ice on a surface

Answer: (A)

The heating of water in a pan on a fire illustrates the transfer of heat from the pan to the water effectively. This process occurs through conduction, where the heat generated by the fire causes the pan to become hot, and in turn, the heat from the pan transfers to the cold water inside it. As the water absorbs this heat, its temperature rises, leading to the water heating up. This is a clear example of heat transfer between two substances at different temperatures, with one substance (the pan) providing energy to the other (the water).

In contrast, the other scenarios do not demonstrate the transfer from a heat-generating source directly to another medium in the same manner. Cooling of water in a freezer involves heat being removed rather than transferred. Heating of air in a room might involve different mechanisms, such as convection, but it does not show a direct transfer from one specific source to a specific substance like the pan to water. Boiling of ice on a surface is less straightforward in terms of heat transfer, as it involves changes in the state of matter (from solid to liquid), which complicates the demonstration of direct heat transfer between two distinct materials.