An electronic system, with closed loop current flow, and relative electrical potentials present across electrical components.

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118 views

What is the area in Faraday's law if we have only a piece of metal moving in a magnetic field?

If a piece of metal of length $l$ is moving with a speed $v$ in a region where there is a uniform magnetic field $B$ perpendicular to it, there will be a potential difference across its terminals ...
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1answer
72 views

Are magnetic hysteresis losses relevant to alternating currents flowing in a wire?

Say we have an AC in a magnetically lossy material, like iron. Because of iron's relatively high permeability, skin effect will be more pronounced than it is in say, copper, so this iron wire isn't so ...
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1answer
34 views

Application of Kirchhoff's laws in circuits with inductors

As we know,the Kirchhoff circuit laws are applicable for conservative electric fields. Now it is applicable for circuits where inductors are present but the field there is not conservative. So how ...
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1answer
38 views

Loading a capacitor in an RC circuit

I have an RC circuit to which I am going to apply voltages of 5V every 100ns. So every 100ns, the capacitor will change its "state" from charging up to uncharging. I have been trying to find the a ...
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1answer
34 views

Can a transformer transfer all power?

How can the transformer transfer exact power from primary winding to secondary winding if there are core losses, eddy current losses and hysteresis losses?
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1answer
223 views

How is the current flow perpendicular to the wire?

This answer gives a great explanation of how surface charge builds up to force the current to move perpendicular to the wire: http://physics.stackexchange.com/a/102936/41086 However, it fails to ...
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1answer
18 views

Why the bulb does not glow in this configuration of batteries?

I connected a bulb to a battery positive terminals with positive and negative terminals with negative . It glows as it should but when i connect the positive terminal of the same bulb to the positive ...
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1answer
40 views

2 simple Generators = Im lost (intensity)

What happens? we have 2 Generators and 2 intensities, when I2 and I3 come together (they have opposite sides ) what happens? I tried writing down the voltage relations but I'm stuck because I don't ...
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1answer
33 views

Electrical Analog of a Chain of Springs

I'm trying to wrap my head around the Force $\rightarrow$ Voltage analogy between mechanical and electrical systems. I have a mechanical system where masses are connected by springs in series, and ...
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1answer
59 views

Circuit breaker Trips during thunderstorm

The circuit breaker at the electrical mains trips at home when there is a thunderstorm outside. Why does this occur?
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1answer
29 views

Name of battery voltage when load connected/disconnected

If I had a 3V battery, and when no load connected it reads 3.2V, and with a load 2.8V (just a hypothetical example), what is the name for these two terms, with a load or no load? I know the voltage ...
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1answer
55 views

Voltage across an inductor contradicts Lenz's law?

Imagine a simple circuit consisting of an alternating current source connected to an inductor. Assume they are connected in the following fashion: AC source - terminal A - Inductor - terminal B - AC ...
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1answer
60 views

Understanding frequency of a signal

I'm trying to understand how can one transmit different signals on a same copper wire using different frequencies. How does the electrons actually interact with the frequency? And how does the ...
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1answer
155 views

Capacitor charging, work done by battery on changing polarity

A uncharged capacitor $C$ is connected to a battery with potential $V$. It becomes fully charged and has a charge $Q=CV$ stored on it. Now the polarity of the battery is reversed. The capacitor will ...
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1answer
87 views

Specific differential equation in RLC circuit

I have been studying differential equations in RLC circuits: (a generator with fixed EMF $=E$,a capacitor $C$, an inductor with inductance $L$ and internal resistance $r$, and a separate resistor ...
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1answer
55 views

Back EMF & Current, how can we make I stable?

Lets assume we have a wire that has $10V$ across and $1$ $Amp$ flowing, now if this conductor is introduced to a changing magnetic field, $-EMF$ is induced, can we control our voltage to increase it ...
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1answer
240 views

The shape of the graph of the equation: $V= -r I + E$

I have recently collected data (for a school experiment) in order to measure the EMF and the internal resistance of a solar cell. The data complied with the equation: $V = -rI + E$, i.e. the voltage ...
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1answer
36 views

Quadrupling Power in a Circuit

If I have a heating wire with resistance $R$ to be connected across a constant potential difference $V$, it would seem like cutting the wire into two (thus each having half the resistance) and ...
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1answer
35 views

High Current at first and then steady from a battery

I just came up with a question, When a battery is connected to a circuit, the current first suddenly peaks up and slowly goes down to a steady value. Why is it so? I have not actually observed this, ...
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0answers
95 views

RLC circuit, turning off the voltage source

An RLC circuit (pictured above) is governed by two equations: $$ -iR=-L \frac{dj}{dt} = \frac{q}{C}+V(t) $$ $$\frac{dq}{dt}=i+j$$ q satisfies the equation: ...
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0answers
99 views

Q factor of parallel RLC circuit in series with a capacitor and resistor

I know that for parallel RLC circuits, the $Q$ factor is given by: $$ Q = R \sqrt {\frac{L}{C}} $$ But now suppose it is connected in series to a resistor $R_2$ and capacitor $C_2$. Would the $Q$ ...
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0answers
76 views

The origin of contact noise?

I was trying to measure the noise of a device with metal probes. I was not sure whether I should trust the results because I was told contact noise might contribute to some degree. I am a little ...
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0answers
54 views

Concepts in Gabriel Kron's later papers

Gabriel Kron was an important research electrical engineer known for applying differential geometry and algebraic topology to the study of electrical system. Towards the end of his career he published ...
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30 views

To find the center of charge in current waveform

I have a circuit for which output current waveform has both positive and negative points. Now I want to get a center of the charge for this waveform (means where my net charge is concentrated ?). Is ...
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44 views

Questions (intuitive) about circuits and the flow of electrons

Why don't electrons accelerate in a circuit? If there is a potential difference and the electron moves in the circuit a force is exerted on it. Why does that force produce no acceleration, keeping the ...
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0answers
64 views

Voltage in a lossless transmission line

I have a question where I'm deriving expressions for different variables within a lossless transmission line. Here's the question as posed: Consider a lossless transmission line of characteristic ...
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0answers
34 views

How do the different types of energy apply to voltage in a circuit

I was just wondering what happens in a circuit in terms of different types of energy transformations. If you apply a voltage to a circuit then electrons start moving (very slowly). Since the electrons ...
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0answers
69 views

Different phase in capacitively coupled RLC circuits

I was trying to work with some data for a lab report I'm writing about capacitively coupled RLC circuits. The setup is pretty simple and looks like that: Where $C^{'}$ is the coupling capacitance. ...
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0answers
103 views

How is derived the relation between capacitances when a $Y-\Delta$ transformation is applied in a capacitors network?

A $Y-\Delta$ transformation can be applied to circuits in order to make an equivalent circuit (but simpler to put in terms of series/parallel devices). Wikipedia and other books show how to deduce the ...
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63 views

How power affects heating of a coil

So I am doing a little research on my own about electronic cigarettes. Most Ecig users value high power at a standard current. This means they buy very expensive, high voltage batteries and put high ...
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0answers
81 views

How to size an electromagnet

How can I size an electromagnet? For example if I would to attract a mass of $x$ kg what are the calculations that I must do to size the ferromagnetic core and of course the solenoid? And thus, how ...
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0answers
156 views

Braess's Paradox in Electrical Circuits

According to this and other similar papers, http://www.nature.com/nature/journal/v352/n6337/abs/352699a0.html, adding a current-carrying path can increase the voltage drop across a circuit. What is ...
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0answers
249 views

Algorithmic approach for applying Kirchhoff's Rules to circuit analysis

Working with Kirchhoff's rules, I am attempting to device an algorithmic approach to finding the unknowns of the problems, I am of a Computer Science background and I am finding it difficult to ...
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0answers
37 views

The mathematical physics of saltatory neuron action potential transmission

Some time ago, I tried to understand saltatory electrical potential transmission on a myelinated axon but have not found a clear mathematical model of this mechanism. I understand the cable theory, ...
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0answers
33 views

Making elementary guess regarding current in AC circuits

I was just studying the comparisons, between A.C, and D.C, and the effects they can produce in electrical circuits (viz, Joule-heating, Peltier-effect and Seebeck-effect in thermocouples, ...
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15 views

Origin of Overpotential in Electrochemical Cell

I'm well aware of the significance of overpotential and how it is defined to be the difference between the thermodynamically determined equilibrium potential and the experimental potential required to ...
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22 views

Replacing diode in circuit analysis?

While analyzing circuits containing diodes in reverse bias I replace it with a pure insulator for simplifying things. Similarly can I replace a forward biased diode with a conductor and a varying ...
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0answers
21 views

How to apply faraday's law to lc circiut

I am having problem on using Faraday's law correctly. When I try to apply Faraday's law to the LC circuit: Assume the top plate of capacitor is positively charged and bottom is negative. So no ...
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0answers
57 views

Power wasted and power delivered?

If a power source is supplying a current I and a voltage V, that travels to its destination through resistors of restance R is the power delivered at the destination = $VI - RI^2$, where $(Pi=) VI$ is ...
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53 views

What is the best way to measure bioimpedance using AC bridges

What is the best way to measure bioimpedance using AC bridges? and capacitances?
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86 views

Thermal noise from capacitor; circuit analysis

I'm trying to model the thermal noise from a capacitor. The capacitor is connected directly into an amplifier with resistance $R_{A}$ and capacitance $C_{A}$. A noisy capacitor is modelled as a ...
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0answers
46 views

What is a non-linear capacitor?

I'm new here. I have a (maybe dumb) question: What are non-linear capacitors? I'm given a circuit including a capacitor and the question says The given capacitor is non-linear with the ...
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38 views

Does back emf occur in transformers?

Does back emf occur in transformers and if so does it reduce the efficiency of the transformer and can it be reduced?
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50 views

Kirchoff Loop and current

The pic of the circuit/problem: I got the problem right, but i want to make sure my reasoning is correct for the current left of the 2.1 V battery. Its the same current as $I_1$ because the ...
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0answers
36 views

Balanced three phase circuit Y-Y with neutral

Here is my equivalent balanced three phase circuit Y-Y with neutral: Rla + jXla is my line impedance by phase. L1 and L2 are my loads. The exercise is saying that L1 absorbs 180 W and 240 VAr, L2 ...
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0answers
145 views

Microscopic model of RLC circuit equation by analogy to continuous medium mechanics

According to the analogy of mechanics and electricity, the 1-D system of damped oscillation is similar to the RLC circuit. The equation of damped oscillation is $$ f=m\frac{dv}{dt}+\gamma v+kx$$ ...
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168 views

Variation of power factor with impedance in a series RLC circuit

I am solving this problem from a previous year question paper A series RLC circuit has resistance of 1k at resonant frequency and half power frequencies are 20kHz and 100kHz. Determine (i) The ...
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0answers
55 views

Blocking electro-magnetic waves between two near field antennas

Its been a while since I studied physics, so pardon my ignorance. I have two near field antennas. The range of the antennas is about 2-3 cm. I am looking for a way where I can block and unblock the ...
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106 views

About electric current analogy

my teacher gave me this analogy to the electric current , the wire is like a pearl necklace where the pearls can move, the current or the movement of electrons is like putting your fingers between 2 ...
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138 views

Transfer functions of active filters

I've been looking for some straightforward method or trick to obtain the transfer functions of active filters (like the Sallen-Key filter, the butterworth or Cauer topology etc...) since KCL or KVL ...