# Tag Info

### Why is there an electric field but not magnetic field on the LHS of the integral form of Faraday's Law

He considers only EMF due to induced electric field. The emf depending on external magnetic field you find missing is called motional emf, and can be present only when a part of the circuit is moving. ...
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### Why is there an electric field but not magnetic field on the LHS of the integral form of Faraday's Law

The answer is that the notation you have used is not correct It is true that $\epsilon = - \frac{d \phi}{dt}$ It is not true in general that this is an electric field, in general: \epsilon =\oint (\...
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Accepted

### What is the formal definition of capacity fade?

Different people would give these things different names most likely. Looking at the graph the blue curves they are the percentage amount of capacity that's been lost with time, so the loss of ...
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### Curl of current density in a wire with variable cross section

Assuming the cone along the Z-axis with length l started at a point and ended as a circle in x and y plane with radius r, assuming that current injected at the cone's start point and collected over ...
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### Why does voltage increase with current?

Similarly, I also looking for a physical explanation behind why the sum of the voltage across the resistors in a circuit has to equal the source voltage [question 2]. Let's say you are at the top of ...
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### Powerline static charge

It was probably a ground default in the area. also hair and fiber stomach gas build up cause the same static stress symptoms.

### Can you loop a charge pump?

When you connect your 2 capacitors in series to the 3rd capacitor, the voltage is no longer 4V, because some charge is transfered to the 3rd capacitor (so as to equalize the voltages). How much charge ...

### How does the thickness of a sample affect the accuracy of four-point probe resistance measurements?

No. It's NOT valid for any thickness, if your probes are applied from the top, as in the linked picture (or as is common with the four probe machines you buy, which will look like the lined picture). ...
1 vote
Accepted

### Can you loop a charge pump?

Near total re-write: Here's an experiment you can do at home. You can do it on a breadboard if you have the parts and the power supply, or you can simulate it with SPICE or, with similar software: ...
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### Can you loop a charge pump?

That is quite simple if you just do it with a few wires by hand! Obviously you should take care not to discharge any of the capacitors by touching the non-insulated part of the wires with your hands. ...
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It is a poor answer and the analysis of the arrangement can be made simpler by assuming that a square, rather than a ring, of side $\ell$, mass $m$ and resistance $R$ is falling. When in a uniform (...
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### What happens to the charges in an inductor when you induce a voltage?

So what is the behavior of the surface charges and the charges inside the coil? Both inner and surface charges will behave the same way (except at high frequencies, due to the skin effect. That's a ...
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### What happens to the charges in an inductor when you induce a voltage?

However, the second inductor is not connected to anything and, hence, there can be no current. There is no load current if nothing is connected to the second coil. But if an ac voltage is applied to ...
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### What happens to the charges in an inductor when you induce a voltage?

If you connect to an ac source you have an ac current in the second wire , same as in a larger transformer ,if you connect to a dc source you have no effect on the second wire except in the first ...
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### Why does voltage remains same over Parallel Circuit

It's actually electrons flowing out the negative end of the battery. There's higher electron pressure on that side of the battery that stays the same all the way up to the resistors. The difference in ...
• 1,668
Accepted

### How can I calculate the magnetic field of a plasma?

Magnetic fields created by currents running in a plasma are no different than those created by currents carrying wire. You need to know the current density in your plasma and then apply Ampere's law. ...
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1 vote

### Will the electrical potential difference between the Windward and Leeward sides of a mountain range generate electrical current?

It is possible that a current could develop in your cable, but it won't be a steady current like you'd want to charge a battery. Humans have actually built quite a lot of conductors that stick into ...
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### Will a battery connected to the Earth eventually deplete?

There can be some transient current for a very short time in nano/micro second order. To make it simple, first connect the negative side to the earth, which will make the negative side at the same ...

### Battery in non-closed circuit with charged body and Earth

In practice, there will be almost no motion of the electrons. A transient electromagnetic wave will propagate outside the conductors and the battery at something like the speed of light. The electrons ...
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### Battery in non-closed circuit with charged body and Earth

Assume that the negatively charged body is a conductor, so that the negative charge $Q$ can move freely from and to it. Then the potential difference of the body with respect to earth $V$ is negative ...
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Accepted

### Battery in non-closed circuit with charged body and Earth

With no current passing through it a battery maintains a constant potential difference across its terminals via an electrochemical retraction. In the situation you have described a current will flow ...
• 98k
Accepted

### Could you make a fire torch with electricity?

No. Yes, you can generate very high temperatures by causing dielectric breakdown of air to form plasma, but this requires unimaginably high voltages. At ~3 kV/mm, air is a very good dielectric ...
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