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A few points of confirmation/correction: Yes the electrons flow in a direction opposite to the "conventional" current. No there is no "deficiency" if electrons - rather they have a different "potential" which is caused by the chemical reactions in the battery. No you don't have to invoke "surface charges" in the wire in order to understand current - ...


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From the engine we recharge the battery using the alternator, Consider the range of an electric vehicle with a fully charged battery. Now, to this vehicle, add a tank of water, an electrolysis system, and a combustion engine that burns the resulting H2 and O2 and drives an alternator. The range of the vehicle is necessarily less than before. Why? ...


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Conservation of energy screws you every time. No, you cannot get more energy out of a system that you put in. However, there is a huge caveat to that statement, which is when the system already contains energy to be extracted by some minor input. For example, a nuclear power plant. However, we know that with chemical processes it is a zero sum game, which is ...


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First let's establish the situation in which the result actually holds. Voltage itself is only well defined in electrostatics, and this result only holds in a steady state. In an ideal battery, there is no energy loss inside the battery during operation, and in the steady state just as much charge flows into the battery as flows out of the battery, and ...


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Imagine a free-standing battery (not connected to any wires) and take a closed loop through the battery, out one terminal, and back in the other terminal. The total work done in moving a test charge around that loop must vanish. For this to happen, the change in electric potential outside of the battery must equal the negative of the EMF change within the ...


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There are also electric fields outside of a real capacitor as well, any capacitor with finite-sized plates. The energy in a capacitor is stored in the electric field, and since some of the electric field is outside the plates, some of the energy is also already outside the plates already. Imagine a bunch of surfaces everywhere in space that are orthogonal ...


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At equilibrium, the field inside an ideal conductor is zero. http://hyperphysics.phy-astr.gsu.edu/hbase/electric/gausur.html#c2 A charge moving through such a conductor neither gains nor loses energy. We can't attach an ideal conductor to an ideal voltage source. Something has to give. There will be a voltage drop along a real wire due to non-zero ...


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In a parallel plate capacitor there's accumulation of electrons on one side and lack of them on the other. Since one plate is in front of another, the fields on each are equal in magnitude and opposite and therefore the field lines are straight (away from the boundaries) and cancel. In a battery the field is chemically produced inside the structure of the ...


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I think the key thing missing in your thinking is that the energy drop across a resistor is not just determined by the properties of the resistor, but also by how much current flows. The cool thing is that no matter what resistors you put in, the current that flows is such that the potential will fall all the way back down. The reason for this is that ...


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The capacitance of your multimeter to Earth completes the circuit. You don't measure the full voltage because the impedance of the meter's stray capacitance to Earth and the meter's finite input impedance make a voltage divider. Even this very small capacitance permits enough current to pull the potential of the disconnected lead of the multimeter away from ...


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Many multimeters have settings for AV voltage and DC voltage, and a wall outlet of 220V is often AC (at 60Hz in the US and 50Hz in Europe), whereas many 5V batteries are DC. Did you set your multimeter to AC when measuring the AC and to DC when measuring the DC?


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Why does Li+ ion attract to the positive electrode (cathode)? Let's first see how we define the Cathode and Anode based on electron movement. A cathode is the electrode from which a conventional current leaves a polarised electrical device. Now, importantly, Cathode polarity with respect to the anode can be positive or negative; it depends on how the ...



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