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The physical 'meaning' of the imaginary part of the impedance is that it represents the energy storage part of the circuit element. To see this, let the sinusoidal current $i = I\cos(\omega t)$ be the current through a series RL circuit. The voltage across the combination is $$v = Ri + L\frac{di}{dt} = RI\cos(\omega t) - \omega LI\sin(\omega t)$$ The ...
There is a physical meaning behind the imaginary component of the impedance. You can re-cast the complex impedance $Z = R + jX$ (using engineering's notation $j$ for the imaginary unit) in polar form to get $Z = |Z|\exp(j\phi)$. $|Z|$ is the magnitude of the impedance, and scales the amplitude of the current to get the amptlitude of the voltage. $\phi = ... 5 Nowadays, the answer is negligibly so. Video cameras now digitise the image as pixels in parallel using charge coupled device technology. Former technologies, however, would emit appreciable bremstrahlung from decelerating electron beams, as I now describe. Before the coming of CCD arrays, the main video technology was the scanned photocathode, also called ... 4 Your eye has a lens in it. Without a lens, the light is all spread out and overlapping, just like you say. The light from any given pixel goes out in all directions, but a lens can make it re-converge back to a point. Hold up a sheet of white paper. Is there an image on it? No, of course not. It has light on it---light coming from each object in the ... 4 If we believe this measurement shown by Omen, smartphone cameras are basically useless below Dose rates of 10uSv/h. The max. exposure limit for a human who is not a radiation worker is 1mSv/year, which translates into roughly 0.11uSv/h. In other words, the camera chip in a phone would have to be 100 times more sensitive to pick up relevant amounts of ... 4 … an ideal power source capable of providing infinite current with no drop in the voltage it supplies. … Let's ignore the effects of current density on superconductors for now. … In these phrases is the explanation for the contradictory possibilities you have computed: you have supposed an impossible circuit. As a mathematical model, the behavior of ... 4 From "The Transistor, A Semi-Conductor Triode", by J. Bardeen and W. H. Brattain, Phys Rev. 74(2), 230-231 (1948): "The device consists of three electrodes placed on a block of germanium as shown schematically in Fig. 1. Two, called the emitter and collector, are of the point-contact rectifier type and are placed in close proximity (separation ~0.005 to ... 3 The electrons need to get from the top to the bottom without any interference from any gas molecules that might be in the channels. If nothing else, collisions with gas molecules will degrade performance. At atmospheric pressure, I don't think the device would work at all. You can blow a hole through an MCP with over-voltage, but I'm not sure how this ... 3 As Kevin Reid aptly explains, the circuit you have drawn is not realizable. But, let's take the closest physical thing you could build, assuming: your voltage source can supply enough energy that we don't hit its limits like all physical things, this apparatus has non-zero size Then, the circuit you actually built is this: simulate this circuit ... 3 As the producer of one of these apps (GammaPix, available for Android and iOS, if you'll forgive the plug), allow me to weigh in here. Yes, smartphone, and other CMOS and CCD cameras, can detect radiation. While cameras are less sensitive then Geiger-Muller counters, specialized solid state detectors, and scintillators, they are sensitive enough for quite a ... 3 A capacitor is often used for "decoupling". The wires into any electrical appliance have inductance (because they are long and thin). This means that if there is a sudden increased demand in current, there will be a significant voltage drop. A capacitor can act as a "tiny battery" that briefly supplies this current while the main supply catches up. A fan ... 3 Yes, there is a fundamental reason why electricity is so universal. It is because matter is made of electric charges bound together (protons and electrons). When you think of non-electric technologies such as the wheel, realize that the wheel relies on the rigidity of matter which depends on the bonds between atoms which are electric in nature. So even ... 3 It's called a diode because the device has two terminals. Devices that have three terminals are called triodes, and those with five pentodes. Words of that type have fallen by the wayside except in the realm of vacuum tube electronics ... except for the word diode, which has hung on. Note that the Wikipedia article that you cite refers specifically to ... 2 Typically it is the ferrite cores in inductors/transformers that resonate mechanically, or through magnetostrictive effects that produce a high pitched whine. Switching PSUs are the main culprit. It can also occur when the EM fields interact with steel components in the PSU. 2 The negative differential resistance creates a special phenomena: under a certain bias and certain incident electron energies, the transmission function through the double barrier is nearly zero. In other words, for a finite voltage domain, the current is nearly zero, i.e. a rectifying behaviour. This can be referred to as "generalized diode", since the ... 2 A couple of suggestions: (1) the EE stackexchange site a better home for this question (2) simply solve for the voltage across the capacitor and the current through the inductor. Once you have those, the energies stored, as a function of time are just $$W_L(t) = \frac{L}{2}i^2_L$$ and $$W_C(t) = \frac{C}{2}v^2_C$$ Since this is evidently a DC circuit ... 2 One form of evidence is the ionization energies of silicon. Nth ionization energy is the energy needed to remove the nth electron. There is a big jump going from the 4th ionization energy (~4000 kJ/mol) to the 5th ionization energy (~16000 kJ/mol). Another form of evidence is the compounds silicon makes. Silicon forms$\mathrm{SiH}_4$,$\mathrm{SiF}_4$, ... 2 For good doping you need two things: (1) get enough dopant in to be useful in changing carrier concentrations, and (2) having an energy level close to a band edge to generate electrons (holes) in the band, rather than making a mid-level recombination center. The below is assuming you are trying to dope Silicon. Data is generally from Sze's excellent ... 2 You are massively overthinking the problem. The collector current is given (by the diagram) to be 150x the base current. The sum of base and collector current has to flow through the emitter... That's all you need to solve this. In particular, a current source will look to a circuit like "whatever resistance" it needs to be in order for the correct current ... 2 Is it possible to produce gamma radiaton using radio emitter? Unlikely. A 'radio emitter' consists of, at least, some type of antenna and a transmitter to drive that antenna. The size of the antenna is related to the wavelength of the transmitted radio wave, e.g., half-wave dipole, quarter-wave monopole. But the wavelength of gamma rays is less than ... 2 Imaginary components in physics often mean phase shifts. In this case the impedance is sort of like a resistance, but it kicks in when there's a changing current by messing with its phase. 2 In this case, the magnitude is telling you how to scale your input signal, and the argument is telling you how to phase shift it. Complex numbers usually represent 'amplification' and 'twist'. So, say, 1 means 'leave it the same', 2 means 'double it', 0.5 means 'halve it', i means 'one quarter turn', -1 means 'one half turn', -3i means 'triple it and give ... 2 Prime suspect is the switching power supply that generates the bias voltages for the tube. As the anode voltage is changed to increase the cathode current (the anode doesn't physically move), the power supply must work harder. Some switching power supplies operate at a fixed frequency, and so wouldn't display this behavior, but others have a variable ... 1 Earth's zero potential is just an arbitrary point similar to (0,0) of co-ordinate system. It has been chosen for Engineering practices because it has very very low theoretical potential (in light with charge at Infinity) and it's easily accessible to everyone and adding charge to it doesn't change it's theoretical potential. With reference to this arbitrary ... 1 In the first chapter of Sze's classic Physics of Semiconductor Devices, one can find: (1) in low electric fields, the drift velocity of carriers is proportional to the electric field strength (section 1.5 in the 2nd edition). It then gives a number of approximations, depending on the primary scattering mechanism. (2) in high field regions, nonlinearities ... 1 Even if the floating Al film is (nearly) disconnected in DC, it is still capacitively coupled to the substrate. Since Kelvin probe techniques use capacitance modulation, the behaviour of the experiment will be more or less identical to the case of a connected film, since tip-film capacitance is so tiny compared to the film-substrate capacitance. It's ... 1 Radios work with a form of radiation called non-ionizing radiation. This means the EM waves contain enough energy to move the atoms (charges) around but not enough energy to break particles loose. Ionizing radiation removes particles because they carry a lot more energy and can break atomic bonds. These travel as UV-rays, x-rays or gamma-rays. In ... 1 Generally in a ferromagnet each atom has$Z-1$paired electrons, with zero net spin, and one unpaired electron. The unpaired electron spins on neighboring atoms like to be parallel, which is why the material has a bulk magnetization. If you try to inject another electron into the ferromagnetic material, that other electron has to go somewhere — into an ... 1 Another interesting analogy, pointed out by Prof. Graeme Milton, can be seen when you examine Maxwell's equations in media at a fixed frequency$\omega$:$\$ \boldsymbol{\nabla} \times \mathbf{E} = i\omega\boldsymbol{\mu}(\mathbf{x})\cdot\mathbf{H}(\mathbf{x}) ~;~~ \boldsymbol{\nabla} \times \mathbf{H} = ...