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

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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
60 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 ...
0
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1answer
169 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
81 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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3answers
205 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 ...
0
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1answer
643 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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1answer
168 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 ...
2
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2answers
150 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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2answers
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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2answers
234 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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3answers
2k views

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 ...
2
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1answer
91 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 ...
4
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3answers
9k views

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 ...
2
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1answer
1k 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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2answers
230 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 ...
19
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5answers
2k views

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
1k 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 ...
2
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1answer
394 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
1k views

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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3answers
1k 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
174 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 ...
0
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1answer
418 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
132 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
113 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 ...
2
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1answer
579 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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2answers
539 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
260 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
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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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0answers
33 views

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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2answers
1k views

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 ...
5
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5answers
2k views

Does current flow back to the source through earth?

We know that if Single Line to Fault occurs, then fault current flows to the earth. I want to know whether the current will return to the source or not. For the current to flow we need a closed path. ...
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2answers
328 views

RC Parallel Circuits [closed]

I am trying to solve the following exercise: A capacitor 27 and $\mu$F is connected to a battery of 21 V through a resistance of 14 M$\Omega$. 1) What 's the charge on his parallel-plate? 2) ...
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4answers
2k views

Transformer: primary side & secondary side current 180 degree out of phase

I am a novice in electrical engineering. I notice that in transformer the secondary side current & current referred to as primary are 180 degree out of phase from each other. But why it is so, I ...
3
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2answers
450 views

What is the physical interpretation of the Fourier transform $(\mathcal{F}Z)(t)$ an impedance?

If I compose a impedances out of smaller ones in series and parallel configurations, e.g. $$Z(\omega)=i\omega L_2+\tfrac{1}{\tfrac{1}{R_1}\ +\ i\omega C_1+\ \tfrac{1}{i\omega L_2}},$$ then I get a ...
0
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4answers
639 views

If components of differing resistance are wired in parallel, how does a common voltage drop arise?

I've been teaching myself DC electronics as a hobby and, although I have a feeling i'm "missing something obvious", I was wondering if someone could help me out. If two components of differing ...
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3answers
120 views

Current flows which way? [closed]

Current flows through a resistor (with no direction since it is not a vector/can flow from any potential)? I thinks it is with no direction since it is not a vector. Is that right?
0
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1answer
58 views

Cell connections

I have an UPS with two 6V batteries connected in series. Is it possible to use the same system (UPS) to charge another two pieces of 6 volts battery if all the batteries are connected in parallel to ...
2
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3answers
1k views

Current Through a Circuit with an 8 Resistor Setup

The following is a question from a practice Physics GRE exam (found online at ETS's website). The circuit shown in the figure consists of eight resistors, each with resistance R, and a battery ...
2
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1answer
428 views

Question regarding Drift velocity in general?

The derivation of drift velocity in case of electrons is equivalent to the case of an charged ionic gas and therefore all the arguments also apply there. Now for an ideal "ionic" gas which interacts ...
4
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1answer
682 views

How can I put a permanent current into a superconducting loop?

I know that you can use induction to create a current in a superconducting loop, but this only works as long as the coil that induces the field has a current flowing through it. And obviously, this ...
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3answers
250 views

potential difference problem?

As far as i know potential difference between 2 points is defined as the negative line integral of electric field between those 2 points. I also know that when magnetic field changes curl of electric ...
2
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2answers
239 views

Why do electrons drift in an ideal conductor, since there's no field?

Suppose a simple circuit with a DC voltage source and a resistor. The voltage of the source will be situated over the resistor. So the electric field (which is the gradient of the potential) will be ...
0
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0answers
11k views

Why do current and electrons flow in opposite directions? [duplicate]

In representing an electric circuit, we would draw the sense of the current from the positive to the negative pole and the electrons from the negative to the positive . But as I know electrons' motion ...
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2answers
203 views

Battery and current confusion?

How exactly does a battery produce a current in the circuit connected across its ends? I dont want to know the chemical reactions in the battery core, but just the essence of it. I believe it doesn't ...
0
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2answers
656 views

How can I solve a circuit of resistances with both a voltage and a current-source in between them?

If I have a circuit that consists out of multiple non-parallel/serial resistances with current/voltage sources in between them like the one below How can I solve a system like that (in this case for ...
0
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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 ...
0
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0answers
39 views

Experimental study of the Photoelectric effect [duplicate]

As I was reading about the experimental arrangement for photoelectric effect, I saw a diagram that puzzled my knowledge of electrodes. I found that in the experimental setup the cathode of the ...
1
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1answer
188 views

Circuit elements classification

I want to understand from theoretical point of view the structure of electric circuits. I don't mean Ohm's law or the Law of induction... E.g. there are resistors $R$, capacities $C$, inductors $L$ ...
3
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2answers
4k views

Why two connected 1.5 volt battery become 3 volt

Why two connected 1.5 volt battery become 3 volt? If one battery plus side is connect to minus side of another battery, there should be a current flow between them until no free charge move anymore, ...
1
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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 ...