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

learn more… | top users | synonyms

0
votes
1answer
57 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 ...
1
vote
1answer
75 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 ...
1
vote
0answers
59 views

What is capacitance, in general?

In circuit analysis software capacitance can be measured between any two nodes of a circuit or of a multiterminal device. In practical terms we take $C_{ij}$, the capacitance between $i$ and $j$ as ...
11
votes
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 ...
0
votes
1answer
186 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 ...
0
votes
1answer
92 views

Closing a switch in series with a capacitor

Suppose we have the following circuit: Such that for $t<0$ the switch M was open. If we close the switch at $t=0$ what will the voltage on the capacitor, $V_C$, be at $t=0^+$? What about $\dot ...
6
votes
4answers
909 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 ...
-2
votes
1answer
106 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?
1
vote
0answers
33 views

Electricity steps/formulae required to answer this [closed]

I need help answering this question and the steps/formulae required. The only answers on my sheet are $0.25V$, $0.75V$, $1.33V$ and $1.50V$ I have worked through it and got an answer of $0.5V$. I ...
0
votes
1answer
63 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 ...
0
votes
1answer
49 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 ...
1
vote
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 ...
1
vote
1answer
18 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 ...
2
votes
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 ...
0
votes
1answer
64 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, ...
0
votes
1answer
52 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 ...
-3
votes
1answer
48 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
0
votes
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
votes
1answer
40 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
votes
0answers
94 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
votes
3answers
72 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
votes
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 ...
1
vote
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 ...
4
votes
3answers
137 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
votes
0answers
26 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 ...
0
votes
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 ...
0
votes
1answer
149 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, ...
1
vote
2answers
45 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 ...
1
vote
2answers
70 views
0
votes
4answers
119 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 ...
-1
votes
1answer
52 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 ...
0
votes
2answers
50 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 ...
0
votes
0answers
26 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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
1answer
68 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 ...
9
votes
5answers
9k views
0
votes
1answer
54 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 ...
2
votes
2answers
129 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?
1
vote
1answer
45 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. ...
1
vote
3answers
112 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 ...
0
votes
1answer
50 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 ...
1
vote
2answers
322 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 ...
0
votes
1answer
77 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 ...
3
votes
1answer
102 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)?
0
votes
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 ...
0
votes
2answers
102 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
votes
2answers
78 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 ...
1
vote
4answers
652 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 ...