Hey this isn't so much a homework problem but one I have just had an exam over. I have absolutely no idea how to calculate it and in all past papers/tutorial questions and the notes, makes no mention of the sort of problem. I'm not bothered over the exact answer, just how you go about it...
I'm going through a textbook, on what is pretty much my first course in Quantum mechanics. I've got to a section were it says that in order for a sinusoidal wave function to correspond to a non infinite probability distribution, there must be a range of momentum, or at least more than 1 momentum...
Thanks, that's a perfect answer. No textbook went further than the fact each mode absorbed energy independently. Never mentioned that each could act as a degree of freedom. (Well two for each polarised state).
Sorry I really should have said mode, not node. Strange as I started using mode correctly. Anyway I've looked at the equipartition theorem in the past. As far as I'm aware every degree of freedom absorbs on average kT/2 worth of energy. However what makes each possible mode obtain such an...
I just found it odd that it was possible for a photon to undergo ~50 photoelectric absorption's all relatively instantaneously. Well with any large degree of occurrence. Turns out that's what the detector relies upon, thanks.
My quantum course starts with the Rayleigh-Jeans law derivation. Whilst I understand most of this, I'm not sure why the average energy of each mode is equal to what they say it is. For instance here is one explanation from hyperphysics:
Assigning energy to the electromagnetic standing waves in a...
I'm looking at scintillation detectors and I'm quite confused to the output of the crystal. My notes just say emission output has intensity proportional to input energy. How though? I mean surely for the Photoelectric effect there is a huge spectrum of output energies depending upon shell...
I'm a physics student so don't do much in the way of electrical engineering, pardon my ignorance. However I'm looking at using a PID controller with a resistance thermometer sensor and heating element plant, with a reference point of some resistance on the thermometer. That is heat up a device...
My question is essentially, how does a DC current not travel at the Fermi velocity? If I have a long straight piece of wire with a dc source at one end and a light bulb the other, I will observe illumination well before the time it takes the electrons to travel according to the drift velocity...
I've been stuck on what I would of thought was a simple/common question but I can't seem to find an answer anywhere. I'm confused as to how a DC current propagates along a conductor (wire) in terms of it's E/H field. I understand that it is these fields that cause the propagation of current...
Thanks very much! You answered 80% of what I was confused about in 1 post. I wasn't expecting that at all, thanks for taking the time to do so. I'm still unsure how electricity propagates at low frequency/dc along a lead other than at the drift velocity. That's a completely different question...
We have just started to look at transmission lines/coaxial cables in one of my classes. This uses the concept of having 2 wires close together causing an impedance/capacitance that allows/controls propagation. However I have never really considered how electricity propagates in the first place...
We have looked fairly extensively at waves on a string without anything on them, however there is a portion in my notes about an infinite string with a mass in the middle. Essentially the setup is that x=0 we have a mass. Here the waveform on each side must be equal as the string is continuous...
For my waves and diffraction course we have had a completely incompetent lecturer. We were looking at standing waves and then all of a sudden he spent a lecture looking at attenuation, not mentioning where it would apply or explaining it particularly well. I have tried to find a textbook to...