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p.tryon
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In an electrical circuit the electrons kinetic energy is transferred to other forms of energy at the components. True or false? If it is false what type of energy do the electrons transfer?
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russ_watters said:False. Electrons transfer electrical energy. Electrical energy has nothing to do with kinetic energy in electrons. Electromagnetism is one of the four fundamental forces and electrical energy is due to moving charges with that force.
No, russ is correct. The point is that electrons are so light and their drift velocity is so small that there is never a significant amount of energy in the form of kinetic energy. It is not that kinetic energy does not exist, simply that it is not relevant for electrical circuits.bjacoby said:Just perhaps, electromagnetic energy just might in some way be related to the effects that have been defined in some circles as "kinetic energy"?
That is rather a different answer than "has nothing to do with kinetic energy" isn't it?
Good point - Kinetic energy isn't really related to one of the fundamental forces, so that part of the sentence is somewhat misleading.bjacoby said:So by your definition of fundamental forces, no such thing as "kinetic energy" exists!
Repainted said:I'm not quite sure how this works. Isn't the reason that electrons possesses low average KE because they've transferred most of their KE to other forms in the components?
For example, in the absence of components(hence no or negligible resistance), an electron traveling through a circuit with a 6V potential across it would gain a KE of 6 eV, which is a quite a large amount of KE for an electron. Hence its maximum drift speed would be 1.03 x 10^6 m/s, and assuming it starts at rest and is uniformly accelerated through the circuit, its average drift speed would be half of that, 5.13 x 10^5 m/s. This agrees with the fact that a circuit with near zero resistance would have almost infinite current flowing through it, since I = nAve and all.
Because of this I concluded that the electrons lose their KE within the components of a circuit converting it to heat and light or whatever the components do, causing them to move at a much lower average drift speed.
Is this reasoning flawed?
p.tryon said:In an electrical circuit the electrons kinetic energy is transferred to other forms of energy at the components. True or false? If it is false what type of energy do the electrons transfer?
Thanks
It is flawed. Let me give you a completely mechanical example about energy that will hopefully help you understand about energy.Repainted said:Isn't the reason that electrons possesses low average KE because they've transferred most of their KE to other forms in the components? ... Is this reasoning flawed?
Repainted said:I am confused by the AC part. Isn't an AC produced by a coil of wire placed within a uniform magnetic field and rotated to change the magnetic flux through it, inducing a potential? Or is this a simplified explanation of how an AC generator works that doesn't talk about EM waves and such?
Also, if this Drude model is inaccurate at describing how energy is transferred to most components, then how is energy transferred from the moving electrons to the components? Or is it something that varies for every component?
Repainted said:Okay I think this sort of clears it up. Thanks a lot.
So to sum it up, the collisions in the Drude model are simply useful in portraying power output due to resistance, but for everyday uses like my computer for instance, it depends on how the individual circuitry is designed to extract power for the power source. Am I right to say this?
Oh and are these 'collisions' in the Drude model really collisions? or as DaleSpam showed with an example, the E-field causing the electrons to simply doing work against another agent continuously and not some haphazard movement through the circuitry?
Repainted said:Oh I see. Its because fundamentally there are only 4 forces, so am I right to say that when we talk of 'collisions' taking place, they are simply some electromagnetic forces between electrons and the particles in the material which affect the electrons motion? Sorry for reiterating what you stated, but I'm doing so in my own terms to ensure I got it right.
One last question, for energy losses not related to heat loss due to resistance, can we still use Ohm's law and such to calculate current and power? Or can we still use Ohm's law, but the resistance here is not the same 'resistance' in terms of the Drude model, and is simply a measure of that component ability to produce power given a certain Voltage across it?
Electrical energy is a type of energy that is transferred through the movement of electrons in a circuit. It is the flow of electrical charges, or electrons, that carries energy from one point to another.
In a circuit, electrical energy is transferred through a closed loop of wires and components. The energy is carried by the flow of electrons from a power source, such as a battery or generator, through the circuit and back to the source.
Conductors, such as metal wires, allow electrons to flow easily and are essential for the transfer of electrical energy. Insulators, such as rubber or plastic, do not allow electrons to flow easily and are used to prevent electrical energy from escaping the circuit.
The amount of electrical energy transferred in a circuit is measured in units of joules (J) or watts (W). This is a measure of the amount of work done by the electrical energy, such as powering a light bulb or running a motor.
Yes, electrical energy can be transformed into other types of energy, such as light energy, heat energy, or mechanical energy. This can be seen in the various components of a circuit, such as light bulbs, heaters, and motors, that convert electrical energy into other forms of energy.