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

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Voltage and Current

I know that as voltage increases, current increases by $V=IR$, but I really find some difficulty in understanding this at the atomic level (what happens with the electrons inside that wire). I ...
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2answers
5k views

How does an electric field come inside a conducting wire inside the circuit? [duplicate]

This has been a really great confusion for me now .... Many places I have read in books that when a potential difference is applied across the ends of a wire a constant electric field is generated ...
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1answer
19 views

Why current of a battery drops continuously in high currents?

I have asked this question on EE SE but could not get a satisfactory enough answer. I have shorted an AA battery through an ammeter. Inititially, the current reading on ammeter was around 0.9 amperes ...
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3answers
5k 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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66 views

Current from Middle Battery in a Two-looped Circuit

With this question, as with many tutorials of similar questions I’ve found online, my textbook only mentions three currents: $I_1$, which flows through the left loop from and to the 19 V battery, ...
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1answer
56 views

How does electric potential relate to charge density in a wire?

Lets say we are talking about a wire with resistance connected to a battery. How is the charge density, taking into account bound and free charges, at two points connected to the electric potential ...
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1answer
53 views

Current through resistors crossing each other [closed]

Calculate the current shown by the ammeter A in the given circuit. I've searched the internet but didn't know how to search for it. Please help
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18 views

Problems with electronic circuits [duplicate]

While reading electronics,I found two problems. It says to get the equivalent resistance of these two circuits. Please help me saying the process to find the equivalent resistance. Here it is-
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1answer
41 views

Current and misplaced switch [closed]

I know this is a very noob question, but i just can't help it. Anyways,here is pretty simple circuit Now after the circuit is changed this way, why is the current going to be infinitely high?? I ...
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0answers
98 views

Which light bulb will burn out? [closed]

We have 5 light bulbs connected in series assuming all bulbs have identical characteristics. The environment is identical for all bulbs. Wire is superconductor (0 Ohm) and is thick enough to deliver ...
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3answers
87 views

Flow of electrons in an open circuit

In a closed circuit, electrons flow from negative electrode to positive electrode. In an open circuit, electrons only flow up to the end of the circuit. Why don't the electrons keep flowing into the ...
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1answer
32 views

Representation of AC through vector

Is there any difference if we use rms value or peak value of sinusoidal wave of AC in phasor (vector representation)? i.e for the length of vector we are allowed to chose one of these,is there any ...
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0answers
39 views

What are the first couple terms of the Taylor series for the evolution of this network of capacitors and resistors?

note: This is a computational problem, and I only need approximate accuracy, so the overall goal is, for a given accuracy and $\Delta t$ to compute the state of the system at $t+\Delta t$ to within ...
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152 views

Why do electric pickles only glow at one end?

The electric pickle is often used as an example of a non-ohmic resistor. In the experiment, electric current excites the sodium ions inside pickle, producing very bright and intense light effect. What ...
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27 views

Resistance used to get maximum illumination with proper security

In which way a resistance is to be connected with a bulb labelled 120V-60W when it is connected with 220V DC source so that maximum illumination with proper security is maintained? What is the ...
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2answers
44 views

Please explain the phrase 'resistance'?

When electrons move against the opposition of resistance, "friction" is generated. Just like mechanical friction, the friction produced by electrons flowing against a resistance manifests itself in ...
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1answer
175 views

In an RLC series circuit on resonance, how can the voltages over the capacitor and the inductor be larger than the source voltage?

Consider an RLC circuit in series, of the form If the source drives the circuit in AC at the resonance frequency $\omega =1/\sqrt{LC}$, the peak-to-peak voltages on the capacitor and the inductor, ...
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2answers
46 views

What is the physical interpretation of Power Spectral Density (PSD) in optical tweezer?

For the calibration of an optical tweezer, the PSD of position values are plotted. If it follows a certain behavior having two regions - free diffusion and potential limited regions, then the trap is ...
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2answers
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4answers
129 views

How could a current passing through a resistance create a voltage as predicted by Ohm's Law?

I have a question about the classic relation $V = RI.$ I know that is the voltage that creates the electrostatic force. But I do not understand how, in a circuit with just a current source and a ...
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1answer
59 views

Power Dissipated by Resistor in AC Circuit [closed]

I'm having a problem with the following review question: Given the circuit: I am asked to find the power dissipated by R1 and C. I know that for C it is 0. For R1, I know I need to use Vrms ...
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2answers
57 views

How is electric field instantaneously generated inside a conductor connected across two terminals of a battery? [duplicate]

I have learnt that the electric field that is responsible for current flow is generated inside a conductor as soon as the two ends of the conductor are connected or brought in contact with the two ...
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0answers
28 views

For series LCR oscillations (resonance), why does current have to be maximum?

I learned about a year back that systems will go into oscillations with high amplitudes if the frequency of the forced oscillations coincide with the natural frequency of the system leading to ...
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1answer
28 views

What the intensity in a circuit when a generator is off?

Let the following circuit I have to compute $U_{AB1}$ (i.e. $U_{AB}$ when $V_1$ on and $V_2$ is off), $U_{AB2}$ (i.e. $U_{AB}$ when $V_2$ is on and $V_1$ is off) and $U_{AB}$ (i.e. when $V_1$ and ...
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1answer
42 views

Heat creation of computer electronics

The first thing I learnt in physics was that whenever anything happens heat is created. Irrespective of the process. With that in mind, electronics clearly create heat (ohmic heating I think?). But ...
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0answers
22 views

E field inside wires during transient state

I've come across an instructive paper which explains qualitatively what happens inside wires of a simple circuit during the transient state, leading to the steady state where there is an uniform E ...
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1answer
70 views

Can iron core from solenoid be diamagnetic?

So... we were measuring RLC circuit, and while we inserted core into solenoid, the amplitude on osciloscope decreased. It would imply, that the core is diamagnetic. But it is original core from PHYWE ...
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55 views

Definition of electric current

As I am taught in school that electric current is the flow of electrons, but in some places I faced another definitions like transfer of energy between electrons. I thought that it is the transfer of ...
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2answers
140 views

Can pulsating DC current be transformed?

Since pulsating DC current is changing, why doesn't it induce a changing magnetic flux in the transformer core? Is it able to induce a transformed current in the secondary coil?
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1answer
46 views

What happens to the resistance, voltage and current when DC passes through saltwater?

I have a circuit of a battery(1.5V or 9V) connected to a multimeter, a connected to 2 metal pieces in water(distilled)(see picture, in place of the LED is a multimeter). With the addition of salt 1. ...
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3answers
114 views

What is the potential difference between $a$ and $b$ in this basic circuit, when the switch is open? [closed]

My professor says the potential difference between $a$ and $b$ is the difference between the voltages on the top left capacitor and the bottom right capacitor. My friend and I however both think it's ...
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1answer
53 views

Does the current in a resistor depend on the speed of electrons?

If the speed of electrons in resistor is slow, then will the current be slow and if the speed of electrons is fast, then will the current be fast? Does the current in a resistor depend on the speed of ...
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2answers
334 views

Does the speed of electrons depend on energy?

I would like to know whether the speed of an electron depends on energy. If yes then in a circuit when electrons flow out of a resistor the energy decreases by a considerable amount, leading to the ...
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1answer
103 views

How do these voltage vs. current graphs demonstrate how the resistance of each conductor changes during the experiment?

The method for the experiment was as follows: Connect the circuit shown above using the globe as a conductor and then replacing the globe with a 10Ω resistor. In each case record the voltmeter and ...
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117 views

If current takes the path of least resistance, why do parallel circuits work? [duplicate]

Why doesn't all the current flow down the path with the weaker resistance instead of dividing and going through both resistors (in a parallel setup with 2 unequal resistors)?
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6answers
14k views

Finding equivalent resistance in complex circuit

In my previous Phys.SE 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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2answers
117 views

Is resistance the gradient in a $V/I$ graph?

We have a circuit where there is a variable resistor, and we increase this resistance at a steady rate, while increasing current. Thus we have increasing voltage. The gradient is defined by $dy/dx$. ...
2
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2answers
103 views

Solving circuit problems

I'd like to know why in a parallel loop, the voltage, along with the current, isn't divided. e.g. in this image from a youtube video the voltage in parallel loop is the same across both ...
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743 views

Measuring electric conductivity

My daughter is doing a science experiment on which metal (e.g., copper, silver, aluminum, iron) has maximum electric conductivity. We are assuming we can accomplish this by using different metal, 3 to ...
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3answers
156 views

How does an ammeter in a circuit work?

Apologies for this simple question, but I'm having trouble grasping the concept of how an ammeter works. Taking the following circuit as an example: When the switch is closed, current flows ...
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2answers
16k views

How do I calculate output voltage from a given supply voltage and resistance?

I have searched everywhere but I can't seem to find out how I can calculate the output voltage (or voltage over a component) from the resistance of a resistor (or other component) and the supply ...
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1answer
38 views

Would optical signal processing still suffer from slew rate?

In electronics, analog signal processing/computation suffers from parasitic capacitance which leads to slew rate—which is the maximum change of voltage allowed, so handling super-high frequency ...
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2answers
99 views

Applying the Symmetry of DC Circuits

While practicing for a notoriously difficult exam I have continued to come across questions like the following and despite my efforts to find resources on them, I can't seem to make sense of it. ...
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2answers
112 views

In a circuit one light-second long, does it matter where in the circuit the switch is placed? [duplicate]

I was looking at this textbook example that was posted to reddit: The accompanying comments basically thrashed it saying everything was wrong. I had a specific question about it, though, and this ...
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1answer
70 views

Why is it necessary for a circuit to be complete?

Can electrons not flow through a load if they do not have a path to flow to the positive terminal of the battery? Why is it absolutely necessary for electrons to end up at the positive terminal?
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137 views

How uniquely determined is the impedance of an infinite-chain circuit?

A recent question asked how to find the impedance of an infinite chain of series-plus-parallel circuits. The standard trick is to split the chain after the first link, and treat the tail of the ...
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1answer
46 views

Capacitance question

A capacitors capacitance, C is equal to Q/V right? If Q was somehow cut in half, would the potential difference also be cut in half, since V is directly proportional to Q? And if so, Its C would be ...
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2answers
153 views

Determine brightness of bulbs in a sImple parallel circuit [closed]

I have a parallel/series circuit given in the following link: The question, listed here: Suppose that you were to unscrew light bulb $L3$. what would happen to the other bulbs? A. $L3$, ...
2
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1answer
82 views

Visualising current in the LCR circuit

I just went through the theory of the serial LCR circuit. There current and voltage are 90 degrees out of phase with each other. Now I was trying to imagine an animation with just dots. And I ...