# Tag Info

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The potential difference exists between the two plates of the same battery. You don't know for sure if the potential difference exists between two plates from different batteries. Additionally, you're not allowing any current to flow even if there is some potential difference. In other words, you have not closed the circuit. Current can't flow in a circuit ...

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The other answers are good (especially the I = (V1 - V2) / (R1 + R2) equation that we will use) but I just wanted to give you ballpark estimates of some numbers that you can expect to see. Imagine that you are going to do this to a 9V battery and a 1.2V AA battery, then: V1 - V2 = 7.8V For internal resistances, it's hard to put ballpark numbers in the ...

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The $KV$ in $30KV$ refers to the motor velocity constant $K_v$. It does not refer to kilovolt $kV$, cf. comments by John Rennie.

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It is quite easy to use a step-up converter to generate almost any voltage. The question is "voltage at what current". The power a battery can deliver is finite (power = voltage times current), but you can convert voltages in many different ways. The most obvious is an oscillator (inverter) followed by a transformer and a rectifier, but there are more ...

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I seriously doubt that the batteries were putting out 30 kV. You surely misread or misheard something. The chemistry of batteries is such that individual cells produce from a few 100 mV to a few volts. A 30 kV battery would require 1000s of cells, which would make no sense at all. In addition, 30 kV is much more difficult to handle and would be much less ...

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Another useful analogy, apart from the gravity one described by David Z, is temperature. You can think temperature as your potential, and the heat flow as your current. Two points of space may be at different temperature, but if they are correctly insulated, they won't exchange heat. The heat will flow only if they are connected somehow. For the current is ...

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The analogy of electricity to flowing water may come in handy here. In this analogy, a potential difference is like a difference in height. One lake on top of a mountain and another in a valley, for example, might represent the two terminals of the battery, which are at different potentials. If you think about that situation, it's clear that no water flows ...

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If you insert a dielectric in a circuit, you will not see any current but obviously there is a potential difference across the dielectric. To have a potential difference, you just need an electric field inside the material. This electric field might drive a current if the charges are mobile.

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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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The article you refer to is about the electrolytic splitting of water. A 100% efficient electrolytic cell would require a voltage of about 1.23V to split water, but for various reasons a simple electrolytic cell requires about 1.48V. The difference between the voltages is called the overpotential, and it increases the amount of power needed to split the ...

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A battery is effectively an electron pump. Inside the battery a chemical reaction (typically a redox reaction) pumps electrons from the cathode to the anode. If the two ends of the battery aren't connected to anything there's nowhere for the electrons to go and the reaction stops. When you connect the battery to an external circuit the reaction resumes and ...

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You need to think of batteries as complete units. Inside, you have a chemical reaction producing the EMF. Leads are connected from the anode and cathode of the cell to the terminals on the battery. When you connect 2 batteries, all you are doing is connecting the terminals together; you are not changing the connection to the voltaic cell inside.

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