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

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Why the electric bulb turns on almost instantly when the switch is closed? [duplicate]

The electron drift speed is estimated to be very low.How could there is current almost the instant a circuit is closed?? By the discussions it is known that The information about beginning of the ...
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1answer
77 views

How uncertainties affect values

If I calculate the equivalent resistance of a circuit, for example: $$1/R_{eq} = 1/R_1 + 1/R_2 + 1/R_3 = 1/1472 + 1/3260 + 1/5580 \Rightarrow R_{eq} = 858.22\,\Omega$$ And then calculate its ...
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112 views

Kirchoff's Junction Rule

I understand that the Junction rule states that the algebraic sum of currents going into a junction equals the current going out of the Junction. There is just a wrinkle that I don't understand. If ...
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115 views

Strange electrical circuit

This is a question I would like to have an explanation with: It's in this PDF, question 9. In that circuit, if switch 1 is closed, bulb A burns normally. If 2 is closed as well, do other lamps ...
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482 views

Physical meaning of Impedance

So I have been thinking about the way impedance is defined for electrical systems, and the way it is derived. Even after looking through some websites, I cannot seem to grasp something, which every ...
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80 views

How long should I leave the light on?

I remember my old physics teacher at school saying that if you switch a light on in a room and you're planning to return relatively quickly, it uses less electricity if you leave the light on until ...
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409 views

Why is the voltage drop across an ideal wire zero?

I'm having trouble conceptualizing why the voltage drop between two points of an ideal wire (i.e. no resistance) is $0~V$. Using Ohm's Law, the equation is such: $$ V = IR \\ V = I(0~\Omega) \\ V = ...
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467 views

How does electricity 'decide' on it's pathway? [duplicate]

I'm struggling to understand the fundamental concepts of electricity, more specifically, the way in which it 'chooses' its optimal pathway. I appreciate electricity will always choose the path of ...
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5answers
4k views

Why does voltage remains same over Parallel Circuit

Why does voltage remains same over parallel circuit. If a resistor is connected in the circuit some of the charge should be transformed into heat and make a lack of charge after the resistor (in my ...
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71 views

Simple circuit with resistances

I have a question about a circuit that I made in class! So, we had a circuit with 2 resistors, one of $R_1 = 330 \Omega$ and one of $R_2 = 470 \Omega$. The tension applied to the circuit should be ...
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104 views

Will the rms current be affected by inserting dielectric in the capacitor in an LCR circuit?

MY thoughts: I think it will not be as the expression for RMS value is dependent only on the peak value of current. Is my thinking correct?
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145 views

Does the heat produced in an inductor affected by the total current in the resistance in the circuit?

The energy stored in an inductor depends on the inductance of the inductor and the current flowing through it. But, assume that the switch is opened. Then, does the heat generated in the inductor ...
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65 views

Loop Rule Parts Problem

[Loop Rule Diagram] The problem is thus: Apply the loop rule to abcdefghia and find the expression which adds to zero. I tried this, but I was not able to get it correct. I know that when crossing ...
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2k views

Finding equivalent resistance in complex circuit

In my previous question , situated here , I asked about finding the equivalent resistance of the following circuit : I got some very good answers and some tips. Now what if the same circuit is ...
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2k views

Detecting if resistances are parallel or series in complex circuits

I know how to detect when resistors are arranged in parallel or series arrangement and I can also find their equivalent resistance in simple circuits or when resistances are connected in form of ...
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1answer
138 views

Is this a series or parallel connection?

I am confused how the capacitors in this circuit are connected. $C_4$, $C_6$ and $C_5$, $C_3$ appear to be parallel, but both $C_4$ and $C_6$ seem to be in series with $C_1$ as do $C_5$ and $C_3$. Am ...
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490 views

Calculate for Multiple Resistors with a Bridge

Background A circuit is constructed with five resistors and a battery as shown. The battery voltage is V = 12 V. The values for the resistors are: R1 = 78 Ω, R2 = 150 Ω, R3 = 132 Ω, and R4 = 83 Ω. ...
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2k views

Magnitude of magnetic field at the center of circular wire

I'm preparing for an exam by solving the sample questions , here is the one I'm having difficulty with : Following is the given circuit. Which contains two resistance $R_1$ and $R_2$ in form of ...
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1answer
250 views

$\pi/2$ phase shift in RC circuit

I just recently learnt Alternating Current and RCL circuits and I also learnt about phasers and various graphs. Now I also know that current lags in an LR circuit. My intuitive understanding of this ...
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1answer
51 views

Why junction removal method doesn't work like this?

This is a question from my textbook's chapter on electrical currents. It has a square circuit as shown in figure 1, where all the wires have identical resistivity. While solving the circuit the ...
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1answer
324 views

Electric circuit question [closed]

http://www.fisme.uu.nl/nno/opgaven/bestanden/Ronde1-Theorie-2009.pdf, question 5: You have to calculate Id when the switch at S is opened, when its closed, the Id = 0.5 A. All resistors are ...
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0answers
50 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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1answer
149 views

Drawing the circuit from a differential equation

Can you please help me in modelling a circuit using the differential equation? In the following equation, $u(t)$ is the input voltage and $y(t)$ is the output voltage. ...
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1answer
79 views

While finding the equivalent resistance why isn't the 8 ohm in series with the 5 ohm?

Is there any way to tell if the circuit below is in series or parallel quickly and accurately?
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160 views

Potentiometer voltage change

I'm trying to understand simple things about electricity reading allaboutcircuits.com web. This chapter includes image which´s principle I don't understand. Here it is: When supplying constant ...
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1answer
558 views

Voltage and parallel-plate capacitors

Suppose we have two parallel plates (each of area $A$) spaced with distance $d_1$ acting as a parallel-plate capacitor within a circuit. If the capacitor is connected to a power source with constant ...
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130 views

Voltage reading between hand and 3.3V source is only 0.1mV. Why?

I held one multimeter probe to a 3.3V source, the other probe I held in my hand. The voltage measured between these 2 points was around ...
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2answers
133 views

What does E/M field look like when I close a circuit?

Suppose that we have a charged capacitor with two pins: $ C_+ $ and $C_-$. Suppose that we have a long wire with fixed geometry, that is already connected to the pin C+. Let the ...
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62 views

Does resistance in second circuit changes in transformed circuit?

Let $V_1$, $I_1$, $R_1$ and $V_2$, $I_2$, $R_2$ be voltages, currents, resistance in first, second circuit. And we assume $R_1=R_2$, $I_1\neq I_2$. The conservation of electrical power ...
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155 views

Is $Q=CV$ still acceptable formular on the capacitor charged by the transformed circuit?

Assume there is a 100V to 1000V transformer and the capacitor connected in the second circuit.(You know, transformers have two circuits) The second circuit's voltage is 1000V, but the amount current ...
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Can single DC 1.5V battery generates 1500 Watts power?

Suppose there is a DC $1.5\mathrm{V}$ battery connected with $1.5\times10^{-3}\mathrm{\Omega}$ resistor. Then the amount of circuit current is $I=V/R=10^3\mathrm{A}$. (according to Ohm's law) I know ...
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1answer
85 views

Inductor rise time and inductor wire length

So here is an interesting question about inductors or coils in general. Suppose you had a inductor which was 12 inch's in diameter and say 12 inch's in length and has 100 turns of wire. The total ...
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Why does connecting a battery's positive terminal to the negative terminal of another battery not create a short circuit?

This is a question regarding the physics behind the observation. I have guessed the answer to the question, but I may be wrong, so I want to wait for the responses before posting it. Some major ...
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1answer
793 views

How to find the total current supplied to the circuit?

Recently, I came across a question based on finding electric current of a circuit. Here's the image... I know, by using the formula $I=V/R$, we can easily calculate the current as $V$ is given and ...
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129 views

Cause of electromagnetic induction?

The rate of change of magnetic flux through a surface (open) is related with the line integral over the closed loop binding the selected surface by one of the Maxwell's equation. But that means even ...
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5answers
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Does alternating current (AC) require a complete circuit?

This popular question about "whether an AC circuit with one end grounded to Earth and the other end grounded to Mars would work (ignoring resistance/inductance of the wire)" was recently asked on the ...
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2answers
811 views

Path of least resistance vs. short circuit

Some sources on the web claim that "electricity follows the path of least resistance" is not true, e.g. this physics SE question. However, in every explanation of "short circuits", the author says ...
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1answer
331 views

Graphene batteries/super capacitors

A while ago, there was some news about micro-scale graphene-based supercapacitors and these devices can charge and discharge a hundred to a thousand times faster than standard batteries. Question: ...
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1answer
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Why does the thickness of a wire affect resistance?

For small thicknesses of wire, it's pretty obvious why resistance affects thickness. (The electronics squeeze to get through). But after a certain thickness shouldn't the thickness become irrelevant? ...
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1answer
832 views

Equivalent resistance in ladder circuit

I have stumbled upon a given question I really have a hard time to solve. Basically I need to find an equivalent resistance in some form of "ladder" configuration. Where the chain is an infinite ...
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1answer
128 views

Which direction does the electron move?

If my phone is charging that means it's mass increasing by this Youtube video. Now if an current is flowing from the power station to home, does it mean that electron is flowing from house to the ...
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300 views

Power factor for impedance

I need to compute the power factor for two ideal impedances, a capacitor: $$Z_C=\frac{-j}{\omega C} $$ and a inductor: $$Z_L=j\omega L $$ I know that the power factor is defined as a term ...
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1answer
116 views

Are two touching conductors connected in parallel or in series?

Consider the following problem: There are two spherical conductors $A, B$, with capacitances $C_A, C_B$ resp. Conductor $A$ is supplied some charge and is found to have a potential of $160 \space V$. ...
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2answers
102 views

In which direction should flow of electric current be taken while solving problems?

Consider a simple circuit with a battery of $\theta\ \text V$s, and two resistors of $R_1 \ \Omega$s and $R_2\ \Omega$s connected in series. Let us assume that $R_1$ is connected nearer to the ...
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1answer
434 views

Is the standard explanation for the ring launcher incomplete?

Related: Faraday's law in a ring The ring launcher is a standard introductory physics demonstration that I assume almost everyone has seen (if not, YouTube it). The explanation of why the ring is ...
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426 views

What are the advantages in using 2 identical capacitors?

What advantage might there be in using two identical capacitors in parallel connected in series with another identical parallel pair, rather than using a single capacitor?
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3answers
199 views

Which is more dangerous upon contact, series or parallel capacitors?

If a pair of capacitors were connected up in series, and an identical pair was connected in parallel which pair would be more dangerous to handle if connected to the same voltage source?
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4answers
575 views

Symmetry in resistor circuits

Given 6 points that are connected with each other with a resistor of resistance $R$, find the resistance between any two points. (Answer: $R/3$) (All the conducting wires have the same ...
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What is the mechanism of conduction of electric current in a conductor? [duplicate]

I am just very much confused about what mechanism is followed when we connect the - terminal of battery to the + terminal through a conductor? What happens inside the conductors that makes the ...
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Where does electricity go from a solar panel that is not plugged in to anything?

I found a similar question here on this site, but my question is slightly different. If a solar panel is exposed to sunlight but is not plugged in to anything--dc load, inverter, etc--where does that ...