In the case of the bicycle dynamo some energy will be lost (probably what you mean by "wasted") in the dynamo (it's actually an alternator) some in the resistance of the wiring and some in the conversion of electrical energy to light. When the lights are switched off you can relax a little. If you pedal your bike (maybe 150 watts) and turn on the 3 W dynamo lights then that extra 3 W load will cause the speed of the bike to drop a little unless you input some extra energy. When we use electrical energy the energy is drawn from the source. This could be mechanical (a generator), chemical (a battery), light (solar panel), etc. No, it is not on topic.Įlectrical energy is usually generated by conversion of some other form of energy. * Please, please do not bring beta decay into this discussion. The energy has been transported (with great inefficiency) from the surface of the ocean to the turbines in the dam.ĭunno if this helps - it's always hard to know what will clear up a confusion. The water impounded behind the dam is run through turbines generating mechanical energy. Some of that forms into a river, which someone has dammed. Some of that blows over mountains, and some of that rains down. It imparts energy to the seawater, some of which evaporates. If you're still caught up in the "how can electrons go in a loop but the energy goes from point A to point B" problem, then consider hydropower. If you ignore any losses in the wires, then the energy has flowed from the battery to the light, but the net number of electrons has stayed pretty much the same everywhere. The energy imparted in those electrons in the battery will be converted to light and heat in the light. If those wires are connected to a light there, then current will flow through the light. This potential energy per electron is seen as the voltage of the battery. If I connect a battery to a pair of wires here, then the battery adds energy to any electrons flowing through it from its positive electrode to its negative electrode. This does not mean that energy does not flow, however. We do not, on an everyday basis, create or destroy electrons*, and electrons strongly repel each other and are strongly attracted to atomic nuclei, so any current that flows is forced to loop around and come back to the source. Given how you express confusion over the fact that current can go in a loop yet energy is wasted, I think that you are also tied to the notion that energy must be tied to the matter that happens to be carrying it. You are confusing electrical current with electrical energy.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |