New answers tagged

2

It is like water in a hose. If the hose is full of water, water flows out the end immediately when you turn on the faucet. A drop of water at the faucet pushes a drop next to it, which pushes the next drop. Water doesn't flow that fast. If the hose is empty, it takes a while to reach the end.


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Neutral is a circuit conductor that normally carries current back to the source, and is connected to ground (earth) at the main electrical panel. In the electrical trade, the conductor of a 2-wire circuit connected to the supply neutral point and earth ground is referred to as the "neutral". A difference can occur when either current is flowing down the ...


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Capacitors connected in series $$\frac{1}{C_{\mathrm{total}}} = \frac{1}{C_1} + \frac{1}{C_2}$$ (Where $C$ is the capacitance) Capacitors in parallel $$ C_{\mathrm{total}} = C_1 + C_2$$ As you can see, capacitors are total opposite of resistors when connected in series or parallel More capacitance or $C$ means the capacitor can store more charge. As ...


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An electron gun is used to shoot electrons at the ink which then gives the ink droplets a negative charge, varying based on where the ink needs to go. Then, the charged ink droplet passes between two metal plates, which deflect the ink to its appropriate location on the paper. The ink does not acquire charge from the metal plates, but from the electron gun. ...


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All of the AC motors will create a "back pressure" once power has been removed. I do however not believe you when you say you have a properly grounded piece of equipment. Please note...the grounding system must be complete ALL The way back to a earth ground (grounding rod ect)...grounding cables can have a tendency to create a thin film of oxidation on ...


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Conduction in water is mostly ionic - for pure water you have a very small fraction of ionized molecules (about 2 parts in 10$^{-7}$), so conductivity for pure water is poor. Add a little electrolyte (for example NaCl) and conduction improves. But in an ice crystal, the molecules / ions cannot move, so the main conduction mechanism is disabled. In that case ...


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Noorism philosophy of universe interprets this phenomena as one example to conversion of '' vacuum energy in to EM energy '' that is vacuum energy and EM are inter-convertible.An accelerating or decelerating electrons causes the fluctuation in the vacuum where C N F space time field is present. Charge and spin of electron produces electromagnetic version of ...


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If your question is: does changing the resistivity (rho), while keeping the same the shape of the resistor, linearly affect the total resistance? Then the answer is yes. The "const" in your formula is then determined by the shape of the resistor. If your irregularly shaped resistor is much longer than it is wide, and the width does not change fast, its ...


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It depends on what you have. Sources can be modeled as a current source or a voltage source. If you treat it as a voltage source, it will always output that peak voltage and the circuit current will change according to the resistance changes. If you treat it as a current source, it will always output that peak current and the voltage drop across it will ...


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Although metal wires conduct electricity using mobile (negative) electrons there are many other conductor which conduct electricity using both negative and positive charge carriers. For example the conduction process in liquids is with mobile positive and negative ions and liquids which do not have such ions (many organic molecules) do not conduct ...


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Realistically (statistically) speaking, AC is more dangerous that DC. This comes from the fact that 120/240v AC is the voltage that we are most likely to encounter - which can kill us. The DC voltage that we are most likely to encounter is 12 DC (in our vehicles), and it is very unlikely to kill us. For the case that we are just evaluating equivalent RMS ...


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There is something called a hole, check it out here. This is a somewhat controversial "particle" if you will, because it can be argued to exist as much as it can be argued to not exist. In essence, when an electron escapes its atom, one can say that a positively charged "hole" replaces it (this conserves charge). So when electrons move, holes appear to move ...


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The solution to this interesting question has to involve both (a) the distortion of the electric field of point charges when they move close to the speed of light and (b) time (since the longer we wait the further apart the electrons become, so their mutual force becomes smaller). Since the electrons are moving along the same straight line we can reduce ...


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In the series connection the current (charge passing a point per second) is the same every where because there are assumed to be no sources or sinks of charge and so the charge is conserved - the amount of charge entering is equal to the amount of charge leaving. This is Kirchhoff's current law and there is certainly no accumulation of charge rather the ...


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The traditional electric bell uses an electromagnet to move the arm that strikes the bell. Electromagnets require the core to be low coercivity as a high coercivity causes losses due to hysterisis, and iron happens to meet this requirement. There is nice explanation of the effect of coercivity in the answers to Properties to select suitable materials for ...


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The power consumed by your circuit determines how fast the battery drains. P = I * E: power (Watts) is found by multiplying the current (Amps) by the voltage (Volts). Since your battery has a (reasonably) constant voltage under normal operation, current is the variable here. I = E / R, amps = volts / ohms. If we combine these two equations, we get P = E ^ ...


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Look into Kirchoff's current law. It is simply charge conservation. If a current of 2 C/s flows in, then 2 C/s must flow out. Because charge is not accumulated anywhere. Inflow must equal outflow at every single point in a steady circuit. Mathematically: $$\sum I=0 \quad \Leftrightarrow \quad \sum I_{in}-\sum I_{out}=0$$ When you in a series circuit have ...


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The current flows in the wires of a circuit, carried by the movement of electrons. At any particular time, if you measure the current at two different places in the same wire, you will get the same reading. This is Kirchhoff's current law in action: all the current entering a point in a circuit must leave that point. Any point on your wire can be seen as a '...


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The force between the charges goes to zero. To see this, work in the frame of one of the charges. From its perspective, the other point charge is moving rapidly away, and the field of a moving charge is weaker along the direction of motion, as shown below. One cheap way of seeing this is to pretend the field lines have been "length contracted". For ...


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Often the easiest way to do such problems is using potential rather than the electric field. And always, it is best to use the appropriate coordinates. In this case, cylindrical coordinates with the rod at $\rho=0$ and extending from $z=-L/2$ to $z=+L/2$ are natural. So what you do is say that for an element of rod with a tiny length $d\ell$ and charge $\...


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First I have to ask: does the question mention anything about the distance d? The reason why I am asking is because if d is large enough, we can say that it is in the far-field and we can easily approximate the field values using electrostatic theory treating the rod as point charge Q. I will provide an edit later if you want to use a far-field approximation....


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There is not such an integral because resistance is a property of whole circuits that may be defined in isolation only in an approximate way. The closest I have come to an integral expression is eq. 63 in https://www.academia.edu/1841457/The_Notion_of_Electrical_Resistance


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The answer is "no". Assume that the ground wire has a resistance of 1 ohm, and your step father has a resistance of 100,000 ohms, which is actually a bit lower than the "normal" value when measured with dry hands. This means that your step father will experience a current flow that is 1/100,000 times the current flow through the ground wire, assuming that ...


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My answer is not associated with the forces on electron and changing electric field.I am giving this answer which is just to feel what happens. Change is the law of nature but, no one likes sudden changes. U may call it analogous to the first law of newton relating to inertias. In the similar way, suppose a loop is kept in a magnetic field with a magnitude ...


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When you give charge to any sphere like above, charge first spread throughout the conductor and not only surface. A current flows inside conductor moving electrons and changing electric field in conductor. Now, positive charge then find that outer surface has less potential than inner. They start moving towards surface in form of current. This current stops ...


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When you talk about the current, the electrons enters in the wire from one end and leaves the wire from another end. They walk slowly, however each one pushes the next one in front and you will get an instantaneous current flow (close to speed of light). The ions make a neutralizing background, hence the net charge accumulation during current flow is zero. ...


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Your reasoning is faulty. It is true that in electro-STATICS (ie when there is no movement of electric charges) the electric field inside a conductor is zero. But this is not the case for electro-DYNAMICS (ie when charges are in motion), eg when there is an electrical current flowing. It is also true that, for alternating currents, the current becomes ...


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@CuriousOne is approximately right. Others have thought of it, the url below is a paper from one who concludes with slightly more careful calculations (but still relatively straightforward) that the most one could get in terms of a continuous power from it is 50 MW, and typically a lot less. 50 MW is 5% of a large power plant. http://www.electrostatics.org/...


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For an applied AC voltage, the primary coil has an impedance from self-inductance which limits the current (amperes) flowing through the copper (unless you draw current from the secondary coil). For an applied DC voltage, the impedance from self-inductance is zero, which causes a large current to flow. This current heats up the wire with a power $P=I^2R$, ...


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Fundamental particles like the electron are well-known to have magnetic dipole moments related to their spins. Moreover, the standard model also predicts that they should have small electric dipole moments (EDMs) as well. However, the EDMs predicted in the standard model are very small; they will probably be too small to observe directly for quite some ...


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The power will remain the same for a particular load as we are not changing the load. so if we increase the voltage, the current will decrease to make the net power consumed by the load same as before. If we increase the current, the voltage will decrease for making the power same. The power will only change when we changes the load.


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Within a source of emf like a battery a chemical reaction occurs which moves the mobile charge carriers from a region where they have low electric potential energy to a region where they have a higher electric potential energy. If the charge carriers are positive that is taking those positive charge carriers from the negative terminal of the battery to ...


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At the cathode the reaction is: $$ ne + X^{n+} \rightarrow X $$ where $X^{n+}$ could be $Cu^{2+}$ or $H^+$. The $Cu^{2+}$ comes from the copper sulphate dissolved in the water and the $H^+$ comes from the dissociation of the water: $$ H_2O \rightarrow H^+ + OH^{-} $$ The equilibrium constant for the above reaction is $10^{-14}$ for pure water at room ...


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Charge is conserved, so the equation of continuity should be applied, . It states that the divergence of the current density J (in amperes per square meter) is equal to the negative rate of change of the charge density ρ (in coulombs per cubic metre), Current is the flow of electric charge. So if the divergence of J is positive, then more charge is ...


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Long ago somebody decided that the direction of "conventional" current flow was the same direction as the direction of flow of positive charges. In that convention the flow of negative charge in one direction is equivalent to the flow of positive charge (and hence the conventional current) in the opposite direction. When introduced electricity usually ...


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Nothing "flows" actually. Electrons transfer the electrical energy by hitting each other. And even if you consider flowing, only electrons free. Protons cannot because they're held strongly in nucleus. About charge, textbooks usually refers it as positive. That means, we just take the opposite direction of electron flow as +ve charge (because electrons are ...


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I suspect that your confusion is caused by the difference between conventional current and the flow of electrons. Conventionally the direction of a current is the direction in which +ve charges move, and this direction is from higher potential (more +ve) to lower potential (less +ve). However, this convention was chosen historically before we knew what the ...


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Maybe a slight easier to follow answer, based on the Quora Website The permittivity of free space is a number which allows us to describe how easily (or how difficult) it is for electric lines of force to pass through air, water or any other medium. It's called permittivity because of how much a given substance "permits" electric, (or magnetic in the ...


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It comes from Coulomb's electrostatic law: $$F = \frac{1}{4\,\pi\,\epsilon_0}\,\frac{q_1\,q_2}{r^2}$$ for the force between two charges $q_1,\,q_2$ spaced by a distance $r$. So then $(4\,\pi\,\epsilon_0)^{-1}$ is simply the force between two charges of one coulomb each spaced at a distance of 1 meter. The ${\rm C^2}$ in the unit definition means that if ...


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The motion of electrons in the wires and the voltages can't be "seen" by naked eyes so the whole science of electric circuits is automatically "harder to visualize" than mechanics. But all such laws and phenomena have mathematically similar analogies in mechanics. The voltage is analogous – not only mathematically but physically – to the slope of an ...


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Resistors are usually colour coded and typically have three or four bands some times more). There are three relevant points here. The first is that the colour code of the first three bands gives the value of the resistance. The fourth band gives the tolerance (1%, 5%, 10%), which gives the range of possible values of the resistor. Resistors are mass produced ...


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Voltage is the electric potential. As already pointed out by ticster, it is analogous to the gravitational potential, which can be intuited as the height of a hill on earth (higher points having higher gravitational potential). We all know that balls on a smooth hill tend to move toward the bottom. In the case of a ball on a hill, you might also ask, how ...


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Electricity is not flow of electrons, it is the flow of charge which can be positive or negative. When books tell us that electricity is flow of electrons, they are merely talking about conductors or alloys where only electrons can flow as protons are too heavy to flow. Voltage or the potential difference is generally electric pressure or electric potential....


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Books tell us that electricity is constituted only by electrons. But in reality protons also cause electricity. In some materials like conductors this is an exception as protons are fixed at their places and are too heavy to move. So basically electricity is a flow of charge which could be positive or negative.


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There are some materials whose resistance does not increase with temperature. So in this case if we go on increasing the voltage and in the way increasing the current and the temperature, the resistance wont increase and thus wont remain constant. But when resistance is increasing with temperature along with increase in voltage and current then everything ...


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With static electricity, the electrons cannot move because the material used is an insulator. Hence there is no current. If the material were conductive, then a current would flow, and there would be no accumulation of charge. Electromagnetic fields will induce a voltage in a conductor, so there will be a current as well. You also need to remember that ...


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In simple terms it is a matter of scale. The sort of demonstration you see in laboratories have induced emf of a few volts and currents of a few milliamperes. The resistances involved are relatively small compared with those in electrostatic. When static electricity demonstrations are done, for example with the rubbing of glass with fur, the voltages ...


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It just refers to charge and there is no significant difference


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It only depends on the context you use it: if I understand well the expressions, in the first one "q" means a reference charge that you use to measure the intensity of the force's field in the space; in the other expressions it's just net charge of the system.


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If you connect a battery to a series of resistors, then you can easily calculate the current flowing through the circuit. If you place a (perfect) voltmeter across a particular resistor $R$ that carries a current $I$ it will measure the p.d. across the resistor as $I \times R$. However, if you place the voltmeter across a piece of wire (with zero resistance) ...



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