What is a common effect of energy transfer?

Energy transfer often results in the production of heat or light, which are common manifestations of energy being transferred from one system or medium to another. For instance, when kinetic energy is transferred through friction, it can generate heat, warming the surfaces in contact. In the case of electrical energy flowing through a circuit, it can produce light when it interacts with a light bulb. This transformation and manifestation of energy into different forms—often into heat or light—demonstrate the principles of energy conservation and transformation, as energy cannot simply disappear but can change forms during the transfer process. Thus, the presence of heat or light as a direct result of energy transfer is a clear and observable outcome in various circumstances.