# Tagged Questions

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9k views

### Resistor circuit that isn't parallel or series

What's the equivalent resistance in this circuit (between points A and B)?
97k views

### Why do we use Root Mean Square (RMS) values when talking about AC voltage

What makes it a good idea to use RMS rather than peak values of current and voltage when we talk about or compute with AC signals.
14k views

### What would be the effective resistance of the ladder of resistors having n steps

I'm a tutor. This is a high school level problem. In high school, every one have might have solved a problem of effective resistance of a ladder of resistors having infinite steps. Now the problem is ...
29k views

### What is the role of center-tapping in a full wave rectifier?

Note: I have already tried googling. Although similar questions have been asked on different forums, I couldn't find a detailed explanation, which I could really understand. Circuit diagram ...
11k views

### How does current flow from the emitter, through the base and to the collector in a NPN transistor?

So, I understand that for a NPN transistor to work the emitter-base junction needs to be forward biased and the collector-base junction needs to be reverse biased. I understand how current flows from ...
314 views

### Generators and electric motors

In a diesel generator, instead of using diesel engine can we use an electric engine and connect the motor and generator to the battery? will this make it an infinitely moving system or will the ...
4k views

### Difference between live and neutral wires

In domestic electrical circuits, there are 3 wires - live, earth and neutral. What is the difference between the live and neutral wires? As there is AC supply, it means that there are no fixed ...
26 views

### Estimating the battery capacity using current power consumption and battery percentage

I want to estimate the current maximum capacity (in kWh) having the current power consumption (in kWh) and the state of charge of the battery (in %) available in a time series. I do not have a full ...
642 views

### Electrical flow in a simple parallel circuit

I'm having trouble understanding something in one of my text books: Let’s have a look at the implications of each circuit configuration. Figure 3.13 shows the Conventional representation of a ...
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### Higher dimensional, generalised theoretical digital electronics

I'm learning digital engineering and I'm also a fan of theoretical and abstract physics and mathematics. I find it amazing that you have an algebra that directly corresponds to logic circuits and if ...
74 views

### Laser-induced electrical discharge

Attracting lightning with an ion beam has been done in a lab but how strong of a laser is needed to reach the clouds to redirect the lightning bolt?
26k views

### Why is Near Field Communication (NFC) range limited to about 20cm?

Near Field Communication (NFC) operates at 13.56 MHz. Near Field is the region situated at a distance r << λ λ = c/f ...
3k views

### Strategies against 50 Hz mains hum on detector signals?

I'm having problems with a strong 50 Hz mains hum on signals created by photodetectors. I assume that they are due to ground loops and I realize that the best option would be to remove those. What are ...
209 views

### Building a Faraday cage for mobile networks that is transparent for optical wavelenghts

A friend of mine is working on an architectonic project, where she designs a Faraday cage type of open space built in parks or other public places. The initial thought is to build it from some sort of ...
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### How do you model the resistance across a symmetric sheet of plastic, streched (think ceran wrap) between a circular anode and cathode?

Here is the problem. You need to model the resistance across a circular sheet of polypropylene (plastic). The resistivity of polypropylene is 1E15 Ohms per meter. The expression for resistance on a ...
23 views

### how to reduce the order of the hamiltonian equation for electrical problem given below?

I am having my FYP in this Hamiltonian project to analysis the integrator for Hamiltonian system. Can anyone please guide me how to reduce the equations to first order using substitution method?
3k views

### PN Junction Depletion Region

So it took me a little bit to understand this, but I want to make sure I have a few things right. First of all, when a Crystal Structure with One side N-Doped, One Side P-Doped are in the same ...
309 views

### Could we run an electric car on electric eels?

Could we run an electric car on a tank full of electric eels? I've heard electric eels are around 400 to 500 volts and can keep shocking for up to an hour. They also have a 10 volt system to sense ...
566 views

### Thevenin equivalent of a circuit

Ok so I can't post the image of my question and my attempt at it, so I would like to ask, if anyone knows the steps to simplifying a circuit with dependent current sources, independent voltage ...
4k views

### When does Thevenin's theorem not apply (modelling a power source with a ohmic internal resistance)

Most physics text books say that a power source can be modelled as an EMF with a internal resistance. This is also know as Thevenin's theorem or Norton's theorem. However I have read in some sources ...
9k views

### Current through the reverse biased junction in transistor [closed]

A transistor is a three terminal device. One terminal is called emitter, one collector and in between them is base. Now, during biasing the junction between emitter and base is made forward biased and ...
3k views

### How to calculate the charge and the potential across a charged capacitor charging an uncharged capacitor?

Initially, there is a single capacitor $A$ attached to a power source that charges it to a certain voltage $V$. Once it is charged, it is instantaneously removed and placed in a circuit with an ...
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### How to reduce the order of Hamiltonian equation for electrical problem [duplicate]

I want to reduce the order of this Hamiltonian but I don't know how to proceed. The equations are given below: $$H(p,q) = \frac{1}{2} (kq^2) + \frac{p^2}{2m}$$ This is the Hamiltonian for a simple ...