# Tag Info

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Well, all I know is that with the right hand on the switch, and the left hand on the bare copper wires, I was shocked immediately as I turned on the switch. My conclusion is that electricity is instantaneous to deliver pain!!! Next step is to stretch a wire from California to the Carolina, with me on the switch, and my cousin on the bare copper wires this ...

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Current is not exactly a flow of electrons but rather a flow of charge. Electrons carry charge, so it is related and you might hear it like that here and there. But remember that not only electrons can carry charge, other types of particles can do that to. We still call it current in those cases, because current is just charge per second moving through. ...

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Yes surely, The pulsating DC is impure dc. Each pulse will be creating a change in magnetic flux in the transformer core. If you see the normal ac diagram the wave from 0 to T, It is similar to your pulsating DC diagram, there is a change in flux in transformer in this case. But it interesting to note that the transformer will give the increased or ...

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Is there a small amount of contact information absorbed by both the Electrons at some level. During the repulsion, I'm assuming there is some level of reverberation that gets absorbed by both proton and neutron during the frequency exchange and wave length generated. I'm just guessing here but I would think opposing wavelengths would repel outwards and also ...

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As long as the DC component does not saturate the core of the transformer, the (lower frequency) components of the waveform should be induced in the secondary. Consider, for example, the output transformer of a single ended class A triode audio amplifier Image credit In this case, the primary current is 'pulsating' DC, i.e., the primary current varies ...

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When you first connect the source, there is a very brief transient during which the steady-state DC solution is set up. The speed of the signal, i.e. the electromagnetic wave front that carries the information along the wire, is a bit less than the speed of light because of transmission line effects. Figuring out exactly how long the transient lasts would ...

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The electric tester displays a light when electrons flow through it. When you touch a negative terminal electrons flow from the terminal through the tester and into you. When you touch a positive terminal electrons flow from you through the tester and into the terminal. Either way the light illuminates. The current flowing is so small that you don't notice ...

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Yes it does. Classically, the current density in a conductor is given by $\vec j = e \vec v_D \cdot n$, where $n$ is the concentration of charge carriers, $e$ is the charge of the charge carriers and $\vec v_D$ is the drift velocity (this is part of the Drude theory). The drift velocity is the average velocity of the charge carriers, the idea is, that they ...

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"The frequency doesn't change" is only true when the core is perfectly linear. For a real transformer, there will be some nonlinear effects (saturation) meaning that the sinusoidal input waveform will create harmonics in the output - second harmonics and higher frequencies will appear. But if you ignore those, then the flux change will vary sinusoidally at ...

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Let $\color{blue}{i=i_0\sin(\omega t)}$ be the input alternating current to the primary coil with a frequency $\color{red}{\omega}$ then the voltage induced in the secondary coil of transformer is given as $$V_{in}=-M\frac{di}{dt}$$ Where, $M$ is the mutual inductance setting the value of $i$, $$V_{in}=-M\frac{d}{dt}(i_0\sin(\omega t))$$ $$=-Mi_0\omega ... 0 Your concepts of AC needs to be revised. The Alternating Current is nothing but DC which changes with magnitude and direction with respect to time. In the above diagram the AC from 0 to T/2 is in forward direction( let's say) this is a matter of fact DC but changing magnitude with time. So if we apply calculus instantaneous Dc will have lorentz force in ... 0 If the question is viewed correctly the batteries are not connected to each other, therefore it is an open circuit. Or if it is connected the batteries are facing each other and the values are not mentioned and so let us assume they are equal. Then the net voltage is zero which is the same as no voltage so V across the 4 ohm resistance is zero. 0 if you imagine correctly, the magnetization and demagnetization is happening at the frequency of the AC supply. Therefore when primary side changes flux in one direction there is the same change in the secondary side and the same time interval. The same way the opposite direction in another same interval of time. So the frequency the Primary AC had will be ... 0 Transformer work on mutual induction. Due to this frequency always be constant. Read mutual induction carefully you will get your answer. V=L(di/dt) 0 How [is] electrical energy is transfered [through] a wire In isn't really, the energy comes in front the side and the charge flows through it and the two are different. Let's talk about the energy. Firstly, the electrons fields and magnetic fields themselves have energy. Secondly, when you charged up the battery you changed the electric and magnetic ... 5 Specially if length of the wire was large, say 3 * 10^8 meters, then would the movement of electrons on one end of the wire be "in sync" with movement of electrons on the other end? No, they wouldn't and this fact is crucial for understanding antenna operation. Note that even short conductors become electrically long if the frequency is high ... 10 As the other answers point out, there are a vast number of electrons in a piece of wire, and no single electron must traverse the whole circuit for a current to flow. You can think of an ac current as more of a sea of electrons sloshing back and forth. I'll focus on your second question: How would the electron flow in DC circuits work if a bulb and a ... 12 Because of electromagnetic forces, all of the electrons in the wire are displaced towards A with a certain velocity causing a positive current towards B. The electrons have a small drift velocity, not moving much. Although your light turns on very quickly when you flip the switch, and you find it impossible to flip off the light and get in bed ... 2 You can determine the charge of an electron from a static measurement in one frame. Another frame could determine the charge of an electron from a static measurement in their frame. And they might agree or disagree. We postulate they agree, but we had three options: We could postulate that whether or not something is an electron depends on your frame ... 1 Think of AC as something that starts out as a positive DC voltage. Then it starts going in the opposite direction. Then back again. And continues doing that over and over. Then smooth the current change out and make it sinusoidal. Now you have AC. 1 It is due to the electric field that is set up that will cause the electrons to move. The drift velocity of the electrons is much slower. There will be a delay in switching on the bulb, and it is equal to approximately l/c, l being the length of the wire. Your diagram is not exactly right, as it shows as if the electrons are being produced at one end and ... 0 Expanding on Kavan's answer, I'd say that since the two ends of the cell are facing each other (as in they cancel out) that the dots could also be interpreted to do the same. Usually dots correspond to a series that follows the same pattern given by the first term (in this case the cells that cancel out). So I'd say 0 is your best shot. If the cells aren't ... 0 I think that, if both batteries have equal potential difference, then the net potential difference will zero between any two points of circuit, so the answer is zero. However, this is a guess, since no information is given and both batteries seem identical in the figure. 0 only a charged body has electric potential around it. Since the person was positively charged by rubbing on carpet, he has a pistive potential around him. when person rubbed his foot on carpet he lost some of its electrons to carpet giving him positive charge. The definition given in book meant to present a view of how to calculate potential around a charged ... 0 Electrons do move, but much slowly, when you are, for example say lighting a bulb, you give a voltage (Potential) across both the ends of a wire, this Voltage (potential difference) induces a an Electric Field, this travels at the speed of light, the wire just acts as a path for the electric field, the electrons start moving due to this electric field, so ... 0 In circuits it's obvious what a potential difference means, but I agree that it's harder to see what potential means for an isolated obect. To address this we have a standard that the potential of a unit charge is zero at infinity. That is, if you take the unit charge an infinite distance away from the object you're considering, then the potential on the ... 0 V = iR but P = iR^2, so if the current, i, stays constant but if the resistance, R, increases, then the power, P, increases too. 1 If you are comparing two voltages with identical currents, you cannot be talking about the same bulb in both cases. This means that you are comparing two different bulbs, and there is no way to tell which will be brighter, since different bulbs can be designed for different luminous efficacy, which is light per unit power. For instance, a bulb can be ... 0 Q1. "from the above values we can calculate Power(P) as P=V∗I" A1. Yes. Power=10W Q2. "If voltage is amplified or raised to 4 times that makes V value to 20 V, what happens to the values of current and power." A2. Assuming your load is a resistor, then your original load resistance was 5V/2A=2.5Ω. Therefore, if you increased the voltage to 20V, your ... 5 Metals are good conductors of electricity because the outer (valence) electrons of the metal atoms are only loosely bound to the nucleus and form molecular orbitals known as the conduction band. Electrons can move more or less freely through the conduction band and so metals conduct electricity generally well. When a metal is chemically oxidised its outer ... 0 It's because valence electrons are bounded. For example, consider Si and SiO2. While Si is semiconductor, SiO2 is insulator because it has no free valence electrons. BTW, many metal oxides ARE NOT in fact insulators - for example ZnO, Fe3O4 are all conductors. But it's true that oxides of metals have lower conductivity than pure metals. 0 Because the current also flows through the battery. Actually in metallic conductors, it is the electrons which flows through the conductor. Read the mechanism of any simple cell, e.g. Electrochemical cell. If the elctrons were not to flow through the battery then they would eventually diminish the charge at cathode and anode of the battery. Then the internal ... 1 Why and how does a resistor limit the current flowing through the entire circuit? doesn't it limit only the current that is flowing past and after the resistor? First, this is a DC circuit (ignoring the switch) which is to say that the circuit voltages and currents are constant with time. Since that is the case, by conservation of electric charge, ... 1 Two questions: How can the ammeter tell how much current is flowing the resistor? since it's "behind" the resistor? There at least several means that current can be measured using different technologies. The early ammeters used galvanometric technology where a coil in the galvanometer becomes part of the current path. The coil generates a magnetic ... 0 It is not that it is just necessary. Electron flow, in the first place, OCCURS due to the potential difference between the 2 terminals - negative and positive terminals. Emf or potential difference is the driving force of the electrons in the electric circuit which causes the electrons to flow from the negative terminal to the positive terminal. If the ... 2 Let's think about the circuit you drew. It contains a battery, switch, bulb, and a very large inductor. In fact, the inductance of a wire that goes 10 times around the Earth can be calculated (I am going to assume an air core - in fact there is a piece of iron in the middle of the Earth which makes the resulting inductance greater).$$L\approx N^2 R \mu_0 ...

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Electricity actually flows faster than the speed of light. If you think of electrons as each having a little engine, it makes it very easy to understand. I hope this helps. Edit: There seems to be some confusion as to my statement so I'm going to clarify. Okay. Then. Imagine I've got a block. I pull the block. It moves. Now, imagine I've got two blocks, ...

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You are right. Voltage is an electric potential difference. The concept of potentials is more general (e.g. gravitational potential) in physics.

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We know that electricity cannot pass through glass and wood There is no such thing as a perfect insulator. There is always some minute current flowing through any insulator, including glass and wood. There are ways in which the resistance of an insulator can be reduced. One way is the one you mentioned: a very wide block of it will conduct more than a ...

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Lets do the arithmetic, as suggested by Energizer777 $$R= \frac{\rho L}{A}$$ $$\rho_{copper} = 10^{-8} \Omega m$$ $$\rho_{glass} = 10^{11} \Omega m$$ How wide a piece of glass would I need to have resistance (per meter length) equal to a very fine copper wire with a radius of 0.1 mm? The area of my copper wire is $\pi r^2 = 3.14 \times 10^{-8} m^2$ The ...

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One way is to connect the ignition to a high voltage (10kV) capacitor. Then the energy is: $$E = \int VI d t = \frac{CV^2}{2},$$ where $C$ is its capacitance and $V$ its voltage, assuming that you connected it and did the measurements so that energy losses are negligible.

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An external electrical field leads to rearrangement of the charges, and this cancels the field inside. Electric fields (applied externally) create forces on electrons in the conductor, creating a current, which will further result in charge rearrangement. The current will cease when the charges rearrange and the applied field inside is canceled.

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Any wire circuit will have inductance and capacitance between the "outbound" and "return" wires - this immediately follows from very basic laws of physics, and in fact is intimately related to the finite propagation velocity of the electrical signal. The expression $$u=\frac{1}{\sqrt{LC}}$$ would give an infinite velocity if either $L$ or $C$ was zero... ...

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Emf is the force at the terminals & within the circuit. It is proportional to the energy stored in the cell & it varies throughout a circuit depending on how the energy moves through the circuit components (higher resistance components dissipate more energy within them--which is what causes a proportional voltage drop (higher Vd with higher ...

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The reason I give is simply that attraction from some opposite charge induces motion in an electron. The resistance to its flow is caused by the medium. If the medium was empty, there would be no resistance, hence empty space should conduct electricity better than copper wires! A metal wire is conductive because metals have lots of energy levels near ...

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The answer is yes. There are hundreds of facilities all over the world called synchrotron radiation sources where electromagnetic radiation with different wavelengths (ranging from IR to hard X-rays) is produced by circulating electric currents. However, I would not call them antennas.

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$$V = {v_r}(t) + {v_c}(t) = i(t)R + {1 \over C}\int\limits_{{t_0}}^t {i(\tau )d} \tau$$ Differentiating wrt t: $$RC{{di(t)} \over {dt}} + i(t) = 0$$ Solving differential equation: $$I(t) = {V \over R}{e^{{t \over {{\tau _0}}}}}$$ From this equation we notice initially at t = 0 $$I = {V \over R}$$ As time is increasing current starts decreasing until at ...

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By capacitor charge is meant the absolute value of the charge on each capacitor plate: $\mid Q \mid$. If the battery generates the potential difference $V$ and you connect the capacitor to the battery through a conducting wire, as shown in your picture, once the equilibrium is reached each plate of the capacitor will have a charge $Q = CV$, where $C$ is ...

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