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SPECULATION: "Does the salt decompose during the process?" I suspect that it does. The salt ionizes easily and the ions would migrate under the influence of the electric field. In so doing, they will further ionize the air they traverse, creating a stream of charge carriers. As the electrodes are pulled further apart, the energy available for ...


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Well, I have a way of remembering if you live in the UK - you always drive your motor on the left! The diagram is correct - it shows what force will be exerted by the external magnetic field on the current carrying wire. The direction of the force is found from the left hand rule: splay your thumb and first two fingers out so they are mutually at right ...


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The image you've linked shows us how to find the magnetic field associated with a long current-carrying wire. But we're interested not in the field that the wire creates, but rather the field that the wire experiences. The fields that a charged particle generates don't influence itself (see, perhaps, this question). And so all we need to worry about is: what ...


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I've found an explanation. As Duncan said, as the sum of the charges stays equal the greatest product of two integers with a certain sum is half of the sum when (for example 5+5=10 and 5x5=25 is the greatest product. NOTE: Here the sum is always even as we take two equal charges 'q' initially). Hence all other series yields a force lesser than the ideal ...


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As long as your product $|q_{1}||q_{2}|$ remains the same as in the case where you had the equally charged spheres, then yes, you will get the same value for the angle (provided the masses are equal). This is because the electrostatic force acts equally on both charged spheres.


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For a given amount of resistance (combined resistance of all the circuits in your computer, or home, or city), the amount of current which flows is proportional to the voltage. (I=V/R) When lightning strikes a line, it induces a voltage spike. Traditional circuit breakers are current-sensing devices (whether solid state or electromechanical). So, a ...


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The Lorentz force on a charge in an electromagnetic field is $$F=q(E+v \times B) \ \ .$$ For an electron between the cylinders, $q$ is negative, and $E$ is defined as pointing outward, so the electron will experience a force radially inward. But due to the unfortunate sign convention used for currents, electrons flowing inward means that the conventional ...


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Yes - electrons flow from the negative to the positive, so in the opposite direction to the conventional direction of the electric field (which points from positive to negative). So if the E field points outwards, the electrons flow from the outer to the inner cylinder. The direction does not affect the answer (the calculation of the flow) though - at least ...


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What you have described is the reason that conductors (such as metals) will act to reduce any polarisation within their structure. Polarisation is an imbalance of charge. In an object with a neutral charge overall, one region of the object may have a surplus of electrons, and thus have a net negative charge, and therefore another region will have a deficit ...


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There's a problem in that you are assuming that all current takes place in a circuit. But in some circumstances, like in a lightning strike or other form of electrostatic discharge for example, a current exists for a while, but it does not take place in a circuit.


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If you have a complete circuit, every piece of metal will gain and lose the same number of electrons and will not have a net charge. If you connect two plates, one to each end of a battery, the battery will take charges from the plate connected to the positive terminal and send charges to the plate connected to the negative terminal until the voltage ...


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For a capacitor, the voltage across must be continuous since the current through since $$i_C = C \frac{dv_C}{dt}$$ Since the current through is proportional to the time derivative of the voltage across, the $v_C(t)$ must be differentiable, i.e., there can be no discontinuous change. There is no such limitation on the capacitor current, the direction ...


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When the current stops, the magnetic field inside a conducting loop diminishes, this produces an Electromotive force ($\nabla \times E=-\frac{\partial B}{\partial t}$). This force can be looked as "resisting" the changing magnetic flux field and producing a current to counter it.


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Fresh fruits can be used as battery, for glowing bulbs, but how this is possible? I mean how electric charges can flow through fruits? Do they contain chemicals like cells? Potatoes are normally used as battery cells since they contain phosphoric acid(whereas acid batteries contained sulphuric acid) in their juice. The mechanism is nearly the same ...


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Also, say, if the external device is 11,000 mAh, then, what if at some state, such as when it reaches 3,000 mAh, the voltage falls to 4.3V, then can it still charge another device that is 5V? Or can the full 11,000 mAh energy all go to the other device? You are correct that a real battery cannot push out all of the available charge at a constant ...


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Fruits can be used as part of a battery. Fruits typically have a weak acid in an aqueous solution. Because the acid can dissociate, it is usable as a cell's electrolyte, allowing a net migration of ions from one electrode to the other. You would still need appropriate electrodes, which contain materials that participate in the chemical reactions to ...


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You can only measure a part of EU compliance. By using your utility meter and measuring the difference between the power consumed over say 10 minutes with the appliance on and off (with everything else in the house as off or steady as possible), you can measure consumed power. However, that's just one part of EU compliance. The other is power factor. ...


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Your requirement that the measurement be made with equipment available in a kitchen is a severe constraint as I can't think of any way of measuring the electrical power supplied. If it's impossible to measure the electrical power in then the only other approach is to measure the thermal power out - i.e. measure the heat produced by the appliance. Given that ...


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If atoms have well defined energy levels and those differences correspond to the frequencies of light that can be absorbed, how is it that opaque objects absorb all or most visible light frequencies get absorbed Photons in almost all frequencies hitting an object are absorbed in different ways (absorbed, reflected, refracted, scattered, ...


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If atoms have well define energy levels and the differences correspond to the frequencies of light that can be absorbed, This is correct how is it that opaque objects absorb all or most visible light frequencies get absorbed and you basically don't have any visible light coming out on the other end? The crux of the matter is the word "objects". ...


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In layman's terms.Elect is inverse mag.Hold powerful magnets on opposite sides of a thin glass window.Report findings.Next q.v.fiber optics.Photons being electro messenger particles. The longer and thinner the glass rod,the greater charge on surface possible. A magnetic field does not transmit through fiber optic thread. Good thing. Glass (silica) is a ...


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Conductivity is not just about how tightly bound electrons are, but equally about how easy it is for them to travel. Example: a bunch of islands in a shark-infested sea. You cannot swim from one island to the next although it is close. At low tide you can walk across no problem. The first example is an insulator, the second is a conductor. Rubbing (google ...


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An informal definition of insulator is that electrons are bounded enough so that they cannot flow all over the material, they remain next to the atom where they belong. In a conductor electrons can move freely and flow to different parts of the solid, detached from the original atoms. Why that happens depends on many factors, but it does not mean that you ...


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You can build microwave antennas of any desired size and directivity. The thermodynamic efficiency of a properly designed microwave link should be around 50%, even though the cost would be horrendous. And if you really need lots of remote power, you can simply get yourself a nuclear power plant at that location. Not that I can see any use for that...


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The easiest way would be to use an energy monitor device (the most popular one seems to be the Kill-A-Watt but there are others). They simply plug into the wall and then you plug your appliance into it. It displays instantaneous voltage, current, power, power factor, etc. and can keep total energy over time. Another option would be to buy an electric ...


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You have a rather precise power meter in your home, which is a "gift" of the electrical power company. Turn off every other load that is connected to that power meter and do your measurement. Alternatively, you can invest $20 in an electronic power meter that is available online and in many stores.


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The force on a moving charge is the Lorentz force $$\vec F = q (\vec E + \vec v \times \vec B)$$ The "magnetic force" (which is not a Lorentz-invariant term, since electric fields in one reference frame will be magnetic fields in others and vice versa) in a narrow sense is just $q (\vec v \times \vec B)$, which is indeed always orthogonal to the velocity ...


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It's quite common for ac-powered electrical devices which are designed without moving parts to "hum," usually with an audible frequency of 60 Hz, 120 Hz, 180 Hz, or other 60 Hz harmonics. (In other parts of the world, where the power distribution system frequency is 50 Hz, you'd obviously get harmonics of that frequency instead.) For instance, when I'm ...


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Is the shaking immediate upon turning the bulb on or after a while? This could mean heating causes Is this the only bulb doing this or is it same with other (of same type)? This could mean bulb towards end of its life or bulbs of this type do that due to construction of filaments Is this the only bulb doing this or is it same with any other? This could mean ...


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There is no way one can answer this question without further requirements. In practice, engineering considerations will put wireless charging of vehicles probably somewhere between the 20kHz and 150kHz range (unless the regulator permits a higher frequency). Why 20kHz? Because all wireless charging solutions will involve the generation of some amount of ...


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This really depends on the design of the bulb in question. High-power or hard use bulbs have filaments under some tension and strong supports. Other (mainly decorative) bulbs have very wispy support wires and straight, loose filaments. In this case, the wire can be very sensitive to mechanical vibration through the floor. The bulb and lamp ( a bulb will be ...


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Assuming that the bulb is powered by some variation of alternating current, and that there is a static magnetic field present in the environment, the vibration could be caused by the interaction of the fixed external magnetic field, and the alternating magnetic field caused by the AC flow through the filament. Bulb filaments are often in the form of a ...


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The correct answer is "It depends, and the way it's shown, it's neither!". The electric field around a wire depends very much on the electrostatic boundary conditions of the problem (you are showing a ground connection... what, exactly, is that connected to?) and on the frequency of the AC source relative to the resonance frequency of the antenna. Unless you ...


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Supposing that the charger gives the voltage greater than 12 V (say, 15 V), we can estimate 15 V × 100 A = 1500 W, a power of a small electric kettle. It is insufficient to effect an actual explosion quickly, but the battery will possibly immediately start to spew the acid mixed with hydrogen bubbles (note that hydrogen is flammable). Another question in: ...


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“[A]n equal and opposite field” is an oxymoron and gibberish. Henceforth I’ll assume that we have a chemical voltage source there. The Coulomb’s law is applicable in the case of a charged body, a body that has a constant electric charge. A chemical voltage source is a completely different situation: there is no pre-defined distribution of charges (as they ...


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How should it be “very weak”? Its field strength is immense, against macroscopic samples. Sure, one shouldn’t suppose a Maxwellian E-M fields inside a matter, especially an electric conductor – this microscopic field is uncertain. One hardly can understand it thinking about it as a vector or tensor field in the spacetime; one needs QFT. There is a related ...


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They talk about contact voltages because it affects “stop voltage” as measured by their instruments, but it doesn’t affect $\Delta U_{\rm stop} / \Delta\nu$ since aforementioned contact voltages are assumed independent of illumination conditions. Because a photovoltaic cell made of a homogeneous piece of material won’t work. A piece of conductor will not ...


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I hope the cylinder is, although long, not infinitely long? I mean the field must extend beyond the cylinder’s ends. The problem is not well-formulated because the resulting state in the second case depends on how exactly the transition to superconductivity is effected. If you cool the cylinder from inside, it will expunge the magnetic field outwards and ...


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There is no such thing as “conduction of electric wave in conductor” (and I am unsure about where “electric waves” can be observed). There is a conduction of electric current in a conductor. One can say that electric potential in a piece of conductor is always the same (so the electric field is zero inside it), although it is not always so due to resistance, ...


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They mean magnetization of ferromagnetic core: http://hyperphysics.phy-astr.gsu.edu/hbase/solids/magpr.html https://en.wikipedia.org/wiki/Magnetization And yet one (possibly) useful link: https://en.wikipedia.org/wiki/Magnetic_core


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AFAIK these gas-discharge lamp things can work only with AC of a sufficiently high voltage. An industrial 50 Hz or 60 Hz frequency is enough to generate a noticeable current because a human body acts as a capacitor. The voltage does matter because a low voltage (such as 3 V) just can’t ignite a discharge even in a very small lamp.


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Whether EMF is a kind of voltage or not depends on terminological conventions. EMF certainly has the same dimension as the voltage (a.k.a. electric tension) has. They are customarily added or subtracted in formulae related to voltage sources such as $U = {\mathcal E} - I\cdot R_{\rm int}$. But these ${\mathcal E}$ and $U$ are no more the same quantity as ...


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As the hair have negative charge it get attracted to the positive charge of the comb. When we take comb to the bits of paper then it get induced


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Lightning takes a largely random path. This is apparent if you watch the process before the strike: Watch the video -- it is amazing. A somewhat less amazing illustration of the process: This is from NOAA, via Wikipedia. These leaders feel out a path between two objects (like the cloud and Earth), sometimes branching, traveling in complex paths. ...


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There is an ambiguity. Although I did not understand your analysis of the problem completely, charge carriers certainly can run against the (averaged) electric force due to difference in available bands and other particle statistics effects. The gauge freedom is irrelevant. There are two cases for the “ubiquity”. First, these non-Maxwellian deviations ...


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This is really physical chemistry, but since the question is here: When you electrolyse solutions you need to consider secondary reactions that might take place at the electrodes. For example if you produced sodium at the cathode it would immediately react with water to produce Na$^+$ and hydrogen. Therefore the cathode produces H$_2$ not sodium metal. ...


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The distinction between emf and potential difference is often glossed over and often misunderstood so this is an appropriate and interesting question. Since both emf and potential difference are measured in volts, it is quite easy to use the terms interchangeably and, in many cases, there's no harm done but that fact is that emf and potential difference are ...


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You should not think of electrons throughout the circuit as one part having more electrons than the other. You should instead think of the electrons within the conductors in terms of their energy. For example when you connect have a simple circuit with a battery, a set of wires, and a load. When you close the circuit, the electrons at the negative side of ...


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EMP or PD is the "pressure" of the electrons. You can have a very high EMF with no flow at all. "Flow" is actually measured by the amount of charge (Coulombs) per second and is measured in Amperes.


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Yes, you can use the standard formula. the equations \begin{equation} I = C \frac{\mathrm{d}V}{\mathrm{d}t} \end{equation} or equivalently \begin{equation} Q = C V \end{equation} are really just the definition of capacitance. (similarly the equations for a resistor and inductor are just definitions of resistance and inductance) Any real system will have some ...



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