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

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1answer
28 views

Circuit energy evaluation

I saw in a documentary that given a circuit, the electron comes out of the negative side of the battery with some electrical potential energy and upon passing through a resistor it gives up all its ...
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0answers
61 views

How to figure out if an element in a circuit is absorbing or delivering power?

. Eg: In the above circuit. 50v source and 0.2Va current source is said to absorb power.If power is absorbed,what work is done with the absorbed power.
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1answer
46 views

what is the function of Current Source in a circuit?

The voltage across current source is due to current itself or due to the circuit within which it is present.
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6answers
2k views

Intuitively, Why is Power Proportional to $I^2R$

As the resistance of a circuit goes down, the power increases because the current increases, assuming constant voltage. Why is this? I feel like resistance and current are inversely proportional, so ...
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1answer
37 views

Circuit current direction [closed]

Can someone explain to me why the direction of the arrows are drawn the way they are in the electric circuit in the picture.
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3answers
453 views

Is equivalent resistance always lower if we add a resistor to a passive electronic circuit?

How to prove that equivalent resistance of any passive network is always lower if we add a resistor between arbitrary two nodes? Note that this is not necessarily a parallel circuit, 2 nodes that we ...
2
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2answers
39 views

Electrical injuries - Doorknob vs powerline

This is something that has bothered me since high school physics. I have a medical and engineering degree, yet I can't for my life answer this question in a way that's logically consistent in my head....
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1answer
88 views

What's the purpose of capacitors in parallel

In my school textbook it is written that the capacitor acts as a filter, that is, it decreases the fluctuations in the potential difference across the load. But since all the components are ...
2
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3answers
131 views

What changes in the electrons before and after a voltage drop?

It is easy to visualize gravitational potential energy as a function of the position of height, and a change in this potential is manifested in a change in height. Further, by the work-energy theorem ...
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1answer
125 views

Effective resistance across 2 adjacent vertices of a dodecahedron with each edge $r$

What will be the effective resistance across 2 adjacent vertices of a regular dodecahedron (12 faces) with each edge having resistance $r$? Here is the source for the problem, it's problem 20. on ...
2
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1answer
59 views

Problem with differential equation RLC circuit serie [closed]

I am trying solve the differential equation of RLC's circuit in serie, I have: $C=4\ F, L= 1\ H$, $R=5\ \Omega$, and $V_e=20\ V$. $1)$ first I got the equation, it is: $i''+5i'+\frac{1}{4}i=0$, what ...
2
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1answer
93 views

Do resistors have internal energy?

I was reading about LC Oscillations in my book and came upon this: In actual circuits,there is always some resistance and some energy is therefore transformed to internal energy. Why internal ...
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2answers
47 views

Why does current density changes but not current? [closed]

let us assume that we have a conductor with a specified resistance ( case 1 ) and a normal conductor ( case 2 ) as shown in the figure , and now we apply an external electric field with a battery on ...
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0answers
30 views

Potential difference across a resistor

I would like to know if the potential difference between the two ends of the resistance is same as the potential difference between any tow points in the resistance whose length is smaller than the ...
0
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1answer
51 views

Electric field along a wire and load

I have referred to many books and all of them apply loss in potential across a resistor only in case of circuits. However, the electric field is present in the whole conductor. Hence the electrons ...
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2answers
8k views

Why does wet skin offer less resistance?

I know that water with salts is a good conductor-However wetting a hand only adds water to a not very conductive surface. How does water actually reduce the resistance of skin? The way I am seeing it ...
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1answer
74 views

Resistors in parallel - Written description of a circuit - drawing needed [closed]

I can't visualise what this circuit looks like from the description Three identical resistors are connected across a potential difference V so that one of them is in parallel with the other two ...
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0answers
603 views

Graph of 1/Current on Y, and R on X axis. What does the intercept represent?

1/I on the Y axis, and Resistance on X. Gradient represents 1/V. Am I right in thinking that the intercept is representative of the Emf of the supply? As I believe the equation would be 1/I=R/V+C, ...
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1answer
98 views

Why does an electron lose all of its energy in a resistor?

Why does the electron uses nearly all of its energy for one resistor in a simple circuit made of a battery, wire, and resistor? I really need to know what happens exactly at the atomic level in the ...
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1answer
179 views

How can the transfer function of an infinite ladder network be used to solve real world problems?

In his lectures on Physics, Feynman illustrates a mathematical 'trick' in formulating the impedance of an infinite ladder, LC network. It basically counts on the assumption that adding one more 'rung' ...
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0answers
27 views

How do the voltage rises balance with the voltage drops in this example of a series circuit?

Consider a resistor and a capacitor in series, with the capacitor initially charged. There is a conservative electric field in the circuit, so $$\oint \vec{E}\dot{}d\vec{l}=0,$$ which gives $$\int_a^b ...
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1answer
107 views

Textbook recommendations for electrical circuits and electronics?

I'm a junior physics major focusing on theoretical physics. I didn't take any courses in electrical circuits or electronics (though I did take E&M). Recently I started feeling that this is a ...
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1answer
25 views

How to compute the charge as a function of time in a simple C-L circuit

I am trying to compute $q(t)$ in a series circuit consisting of a capacitor of plate charges $q_0$ and $-q_0$ and an inductor. The switch is closed at time $t=0$. By Kirchoff's Law, $$\frac{q}{C}+L\...
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0answers
30 views

References on Josephson ring modulators

I would like some good references on Josephson junctions and, in particular, Josephson ring modulators. I know that Devoret has written a handful of papers and notes on JJs, but I am hoping to find ...
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1answer
173 views

Distribution of surface charges in an electric circuit

I'm reading Sherwood and Chabay's brilliant textbook Matter and Interactions, in particular the section that deals with how the surface charges in an electric circuit distribute themselves to generate ...
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0answers
46 views

Diode's volt-ampere characteristics

The Problem is that If the reverse saturation current is $10\ \text{nA}$ ($1\ \text{nA}=10^{-9}\ \text{A}$), Calculate the forward current while the forward voltage is $0.6\ \text{V}$. And explain ...
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1answer
72 views

Applying Kirchoff voltage law to a short circuit

If you consider an ideal wire with no resistance that shorts an ideal battery, the only voltage drop that exists is the emf of the battery, with nothing to balance it. Obviously in the real world ...
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1answer
84 views

RC circuit discharging capacitor, trouble understanding

If we apply loop rule while charging the circuit we get: $$\varepsilon -iR-\frac{q}{C}=0$$ The way I understand, we follow trough the circuit just before the battery, as we move trough the circuit ...
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8answers
3k views

How do electrons “know” to share their voltage between two resistors?

My physics teacher explained the difference between voltage and current using sandwiches. Each person gets a bag full of sandwiches when they pass through the battery. Current = the number of people ...
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1answer
274 views

Why don't you get electrocuted when you jump and touch an electric fence?

I've read that you won't get electrocuted if you jump and touch an electric fence because you aren't closing the circuit with the ground. Which is also why birds don't get electrocuted when they're ...
6
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4answers
1k views

Why is there an electric field in a wire even though it is a conductor?

If you take a perfect conductor, there cannot be a field across it since if there were, the particles would arrange themselves in a way to cancel out the field right? Yet, why does the same not hold ...
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1answer
121 views

Why does the symbol have an arrow? [closed]

What does the arrow in the symbol mean? Does it mean that it is a variable voltmeter and ammeter?
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1answer
66 views

Is the electric field in the wires of the parallel circuit always the same and how that affects current?

When we connect two resistors connected in parallel with a battery, it creates an electric field through this wire. well, my question here: Is the electric field in the main wire is the same as the ...
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1answer
53 views

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
6k 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
20 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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1answer
71 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, $I_2$...
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1answer
60 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
57 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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0answers
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-
0
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1answer
42 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 ...
-2
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0answers
107 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 ...
0
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3answers
95 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 ...
0
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1answer
33 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
41 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 ...
4
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3answers
163 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 ...
0
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0answers
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
45 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
191 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, ...