# Tag Info

33

The electrons themselves don't move all that fast. The wave energy is the part that moves quickly. Picture it this way. You have 500 meters of pipe, with a small hole at the other end. The pipe is full of water and you increase the pressure at your end. Water will flow out the other end immediately. This is the electrical energy (pressure) and the ...

14

In fact, electron's speed is not so fast that light bulb glows up immediately. It is the electromagnetic field which travels in the circuit at near the speed of light that is resposible for it. After turn on the light, electron only acquires a little speed in addition its thermal speed. The thermal speed of electron can be estimated by $mv^2/2\approx ... 4 Depending on your view, there is electronics with other charge carriers. It is commonplace to have semiconductor devices where the relevant carriers are holes! Furthermore, batteries and electrolysis relies heavily on ions as charge carriers (but hardly count as electronics). I guess genuine electronics with ions will be difficult as charge carrier mobility ... 3 According to the Review of Particle Physics (Section 33.7.4 of the 2014 edition) there are two main causes of radiation damage for electronic devices: Bulk damage due to displacement of atoms from their lattice sites. This leads to increased leakage current, carrier trapping, and build-up of space charge that changes the required operating voltage. ... 3 Ionizing radiation loses energy in matter by creating electron-ion pairs. Suppose you have an 1 MeV charged particle stopping in a silicon crystal. The first ionization energy for free silicon atoms is about 8 eV. The ionization energy will be a little different for silicon atoms on the lattice, but not grossly so: your 1 MeV charged particle is going to ... 3 If your phonograph cartridge uses a piezo-electric pickup, the cartridge may have acted as a rudimentary crystal radio receiver. In a piezo-electric pickup, the stylus contacts a crystal and creates an electric current while jiggling as it moves through the grooves of a record. It's likely that while you were jiggling the apparatus, you found the exact ... 3 It just shows that the item is a meter. The arrow represents the indicator on analog meters. 3 can't that internal resistance be measured quite easily? No, it cannot always be measured quite easily as it can be very small. Now, if it's so small, why do we care? Well, we normally use a 4-terminal measurement precisely when the resistance we're trying to measure is itself rather small. If we have some uncertainty in the value of the probe ... 2 Electronics is mostly insensitive to static magnetic fields of that strength. The only serious damage that I would expect for electronic circuits is to switching power supplies (and circuits that are being powered by it) in the case that an inductor core gets saturated. In practice I have been debugging electronics for something like 40 years and I have not ... 2 Electrons and holes occupy their states according to the Fermi-Dirac distribution, which has a single parameter$E_f$, the Fermi level (assume a fixed temperature). Provided$E_f$is in within the band gap and far from the band edges, the (energy integral of) Fermi-Dirac takes an exponential form$\propto e^{E_f}$for electrons and$\propto e^{-E_f}\$ for ...

2

If you take a diode that isn't connected to anything we get the usual depletion layer at the PN junction: And we get a potential difference generated across the junction. Suppose we now connect the two side of the diode with an external wire, then a second depletion zone develops at the connections with the wire: And this depletion zone has a potential ...

2

As a Physics student I've found really useful Jacob Millman's Microelectronics, which offers a thorough insight into the world of Electronics, both digital and analogue. It covers a wide range of topics, from semiconductors to transistors (BJT, FET - both MOSFET and JFET) to operational amplifiers, with chapters devoted to the explanation of the concept of ...

2

The current in other Optoelectric devices like LED and photocells are flowing from a source of voltage to the devices but in case of solar cell, current flows from the cell to the load and thus current in circuit is taken to be in opposite ( or negative direction ). The voltage is still positive. Therefore, the fourth quadrant. Someone else may provide you ...

2

Yes, oscilloscopes will eventually wear out. They last a long time, if they are taken care of. There are many vintage scopes out there that are 30+ years old that still work perfectly. Here are a few examples of failure modes. There are probably more. 1.) Phosphor coating on the inside of the tube wears out, causing the display to dim. 2.) The tube develops ...

2

A capacitor can contain a certain amount of charge for a given voltage: $$Q = CV$$ When you have more than one capacitor in parallel, they have the same voltage (because they are in parallel), and each stores a certain charge. The total charge (at a given voltage) will be the sum of the charges on all the capacitors. Now if you have a certain load (for ...

2

Even in a 'DC' circuit, diodes can be useful for, e.g., current steering. Consider a rudimentary battery backup system: When the primary 14V supply is present, the LED is on while D2 and R2 prevent the battery from charging at too high a current. When the primary 14V supply isn't present, D1 'disconnects' the LED and regulator IC from the battery while ...

2

As you mentioned memristance governs nonlinear behavior of electric or magnetic circuit based on the amount of electric charge which has passed through it. In this paper Strukov et al. from HP labs described properties of memristors and provided fundamental mathematical model. As a physical model they employed metal/oxide/metal circuit where metal is Pt and ...

2

From your question is sounds as if you understand how parallel LC circuits work, in which case it's easy to explain how an LC circuit works as a tuner. Any particular parallel LC circuit has a natural resonant frequency. If we assume the LC circuit is perfectly lossless, then if we apply a driving voltage at the resonant frequency the energy stored in the ...

2

I believe that the reason may be at least two-fold: (1) For dopants to be effective, the energy level introduced by the dopant has to be a shallow energy level, not a deep energy level. A shallow level means that the impurity level is very close to the valence or conduction band, so it is easy to thermally ionize the dopant atom and have its electron (or ...

2

The answer is not simple. The sensor you linked has 4 independent photodiodes, each with its own optical filter, and each gives a different result. In a perfect world, the 3 color sensors would exactly cover the overall spectrum of the white sensor, with no gaps or overlaps. AND the responsivity of each color sensor would be exactly the same as the white ...

2

It is not that the interviewee experiences a longer delay - but that you see the whole scene delayed by the same amount. Delays are caused by a number of factors: sound is conveyed in packets that are digitized, compressed, and converted at various points along their path: at each point they experience at least "one packet's worth" of delays (can't send ...

2

I think it might be one of those things where people do something because everybody does. I agree with you, a figure of merit that includes noise would make more sense. But, as the circuit designer that I am, I could also say that that wouldn't be the end of it. For example, in the classic trans-impedance amplifier used for these kind of detectors the ...

2

Can we have electronics with charge carriers OTHER than electrons? Yes, see what Sebastian said above. And see the physicsworld article Taming light at the nanoscale: "Look around, and you will probably see numerous electronic and optical gadgets, such as mobile phones, personal digital assistants, laptops, TVs and digital cameras. These may all do ...

1

Although there are different types of "radiation," their common effect is to transfer some/most of their energy to the material they "hit," resulting in the breaking of the atomic bonds and or structures of the material. When "enough" bonds and/or structures are broken, the material will fail. Since the electrical characteristics of electronic components are ...

1

A Zener is not like a normal diode. A normal diode lets current flow in only one direction and needs to be installed in the correct direction. A Zener diode is placed in the opposite direction, against the flow of current. A Zener diode will prevent current from flowing until it reaches a certain voltage, depending on the diode rating. Once this critical ...

1

In the first of your data sets, it does look like the white value is (close to) the average of the RGB values. In the second one, the white value is significantly greater (average of RGB ~= 388, but W ~= 639). Looking at the data sheet, the W sensor includes a significant range of infrared in its spectral response (see the graph on page 5) which might ...

1

C2 and C6 are AC coupling capacitors. An AC signal on their input appears on the output. If you just connected these two capacitors together, they would act as a voltage divider - the voltage at the connecting node is the mean of the voltages at the other side of the capacitors. The "weak coupling" comes about from the fact that since the point connecting ...

1

It is not affected at all. There is no net potential difference across the sandwich whether it is part of a circuit or not.

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Assume that the free space is vacuum and the battery is perfectly insulated as well as all the electrical contacts. In this case there are two possibilities for an electronic device to fail: 1. The induced emf in the inductive elements of electronics device because of the changing electrical field caused by the addition of electrons. 2. Most of the ...

1

In regard to the first, we have a 5v supply, which from my understanding means that if you were able to enclose a coulomb of charge eminating from the negative terminal, you'd find that it has 5 joules of energy. This isn't the typical understanding. A 5V (ideal) supply (source) maintains a 5V potential difference across the terminals independent ...

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