Questions tagged [voltage]

Voltage is the unit of measurement for electronic potential, from one point location to another.

189 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
5
votes
4answers
3k views

Charging of a battery

A battery has an Emf 6 Volts. It is completely discharged. It is charged by maintaining a potential difference of 9 Volts across it. If the internal resistance of the discharged battery is 10 ohms, ...
4
votes
0answers
90 views

Skin effect fully explained by plane wave attenuation?

I went over the explanations of the skin effect in multiple sources. However, I still don't understand how the fact that this equation: \begin{equation} (\Delta - \mu_0\sigma\partial_t - \frac{1}{c^2}...
3
votes
0answers
29 views

Can an Opposing Current Create another Opposing Current?

In Inductors when current increases it's magnetic field induces a voltage which causes an opposing current that slows down the rise of the current that initially creates it, but can this opposing ...
3
votes
0answers
153 views

What is a good analogy for electric potential?

When the electrical field was defined I could totally relate to $\vec{E}$ being like $\vec{g}$ in mechanics. But for the electric potential I don't know what would be equivalent analogy. Any ...
3
votes
1answer
87 views

Does charge injection from electrodes increases the total charge in a (semi)conductive channel?

When a (semi)conductor is connected to a voltage bias, a charge is injected by the electrodes. When steady state is reached (constant current flow), does the total charge of the (semi)conductor differ ...
3
votes
4answers
1k views

Electromagnetic field and voltage drop in a circuit

I have been thinking for a while about what really causes voltage drop and how to explain it in terms of what the electric and magnetic fields do. So I've been reading a lot of posts here and in other ...
2
votes
4answers
150 views

Induced EMF vs battery EMF

I am bit confused at whether induced emf and battery emf are same in nature differing just in their source. Does a potential gradient exist in case of induced emf as we have when a battery is ...
2
votes
2answers
154 views

Common potential in Capacitors

If two isolated charged capacitors (of different capacitance) are connected in parallel to each other they acquire a common potential. But suppose if i connect positive plate of one capacitor to ...
2
votes
2answers
66 views

Is the voltage between the two points $A$ and $B$ denoted as $U_{AB}$ or $U_{BA}$? And why?

Consider the following circuit Is the voltage between the two points $A$ and $B$ denoted as $U_{AB}$ or $U_{BA}$? And why?
2
votes
2answers
98 views

What does 'Oppose a Change in Current' really mean from Lenz Law?

We all know what Lenz Law is, but I have a bit of trouble conceptualizing the phrase above. Does 'Oppose a Change in Current' means it will take more time for the current to increase to its maximum ...
2
votes
1answer
92 views

Dual finite parallel disk capacitor; estimating mathematically that the potential or field or distribution is nearly uniform from first principles

Working through Purcell. In particular, doing my best to put everything on a firm footing, mathematically, so that I can understand it. But, I have struggled all week in establishing from first ...
2
votes
1answer
117 views

Electric potentials and superposition

I had a question regarding the addition of electric potentials. Consider two positively charged particles $q_1$ and $q_2$ at distance $R$ apart. Let the charges have magnitudes $q_1$ and $q_2$. For a ...
2
votes
1answer
589 views

How to measure a static electric field?

I looked up google but didn't find any design for measuring electric field that doesn't vary with time. My own idea is to use two parallel plates (like a capacitor but without the dielectric). In an ...
2
votes
2answers
101 views

Doubt about the working principle of a silicon solar cell

I'm studying crystalline solar cell and their working principle, but I still don't completely understand the process. First of all, I understand that we dope a pure crystalline silicon with boron and ...
2
votes
1answer
66 views

what is difference between region around a charge and region out of it?

Basically I want to know what makes a region around a charge particle so affective that another charge will have energy when brought in this region or it will experience a force when enters into this ...
2
votes
2answers
434 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. ...
2
votes
0answers
161 views

Why does electrolysis require a base electrolyte instead of an acid electrolyte?

I am in the process of using electrolysis to remove rust from some old tools. This is the process where you submerge the rusted item in a bath along with a sacrificial piece of metal. You connect a ...
2
votes
0answers
133 views

How much current would be generated by polarity reversal of Earth's magnetic field?

Continuing from my previous question Is reversal of magnetic polarity in a planet an instantaneous occurence? A change in magnetic flux is expected to generate an EMF. In the case where the ...
1
vote
1answer
28 views

Is there a potential difference across the bulb after current passed through a diode?

I understand that voltage can exist without current so what I want to ask is will there be a potential difference across the bulb(situated after the diode) when a batteries supplied energy through a ...
1
vote
1answer
55 views

How same power is distributed in different voltages in power lines?

I have seen when a resistor is connected to a battery, it carries the same voltage across the resistor, if the resistance is changed the current changes but voltage remains the same making the battery ...
1
vote
0answers
44 views

What happens to the potential energy of an electric circuit during a voltage drop?

Is it accurate to say $$ W=\int{Fdx}=\int{EQdx}=\int{\frac{dV}{dx}Qdx}=QV$$ so voltage is like g*h it is a potential field and charge is like mass. We know that the energy flux(vector) is given by the ...
1
vote
2answers
70 views

How is potential difference greatest when battery is not in a circuit?

I was just studying physics and came across this in the textbook that “A cell produces its highest p.d. when not in a circuit and not supplying current.” Could you please explain this? If the cell is ...
1
vote
0answers
89 views

What does EMF actually mean?

After studying EMF in DC circuits I realised that EMF is just the potential difference between cell terminals in an open circuit. But then I was introduced to Faraday's laws of electromagnetic ...
1
vote
1answer
34 views

Confusion about the relationship between current, resistance and potential difference

If the voltage of a component has dropped, what will happen to the resistance? My book says it will decrease but I don't understand the logic. How can current and resistance go down at the same time? ...
1
vote
2answers
40 views

Confusion in usage of formulae for power dissipated in a circuit

When should we use $\frac {V^2}{R}$ and when to use $I^2R$. Because many times they ask about the power without giving details about series and parallel. I am really confused
1
vote
0answers
29 views

Electric field inside a homogenous distribution for slightly different Coulomb's law

I am trying to show that the electric field inside a homogeneous distribution of superficial charge is of the order of magnitude of $\delta$, with: $$V(\textbf{r})=\int d^3\textbf{r'}\frac{\rho(\...
1
vote
0answers
23 views

Open circuit voltage of solar panel in relation to temperature

How do we calculate the effect of temperature on the open circuit voltage of a solar panel? The source: https://www.pveducation.org/pvcdrom/solar-cell-operation/effect-of-temperature offers an answer,...
1
vote
0answers
31 views

Are my voltmeter readings expected for a correct chua's circuit?

I am following this article Robust OP Amp Realization of Chua's Circuit by Kennedy to implement a Chua's circuit. I use exactly the same design as the article; the only difference is that I use a 15mH ...
1
vote
3answers
107 views

Why voltage is same across parallel resistance?

Since voltage stands for energy per unit charge to be used to carry it from one point to another,why should energy per unit charge be same for two resistors of different resistances,?the energy ...
1
vote
0answers
35 views

Resistors equivalent using symmetry and equipotential line

I propose the following statement: In a circuit, while determining equivalent resistance across two points, if the circuit is symmetric wrt the line joining the two points , we may fold the circuit ...
1
vote
0answers
27 views

Why does the base-emitter voltage in NPN transistor become constant

The setup above shows the experiment that I have been working with. During the experiment, the current $i_c$ and the voltage $V_{be}$ were measured for increasing $V_{in}$. At some point, the current ...
1
vote
0answers
466 views

Unequal area's under a graph of induced voltage (magnet falling through a coil) against time - Faraday's Law

I have done an experiment where a magnet was dropped through a coil of wire and the induced emf was recorded. My understanding is that the area's under the positive and negative sections of the ...
1
vote
2answers
69 views

What is the voltage in electrical circuits?

I understand what the voltage is and I realize that the battery makes an electric field due to the accumulation of the charges in the anode and cathode this electric field causes electric potential ...
1
vote
0answers
38 views

Field between 2 electrodes experiment

We were asked to conduct an experiment that is as follows: Connect 4.5V constant voltage across 2 electrodes of thin Cu wire, dipped in a tub of copper sulfate solution. A needle is connected to a ...
1
vote
0answers
18 views

Potential profile defined up to a constant

More of a clarification than an actual question. I'm doing exercises on graphing electric fields and the corresponding potential profiles, and i get the same potential profile as my professor, just ...
1
vote
0answers
135 views

Electrical resistivity calculation of a cylindrical material

I have a copper rod, its diameter is 13mm, and its height is 13mm. I want to check its electrical resistivity. I have tools to give this copper a constant current by two points (the two black dots in ...
1
vote
1answer
122 views

Hydraulic analogy and pressure in pipes

In the latest days I've been quite obsessed with understanding how electricity work through the hydraulic analogy. I still have some problems regarding how "voltage drop" works, and how pressure drops ...
1
vote
1answer
51 views

Question on measuring $I$-$V$ characteristic of a component

When measuring the I-V characteristic of a metal wire/diode/filament light bulb , what is generally the best circuit set up? You can Change the voltage across the component directly using a variable ...
1
vote
0answers
90 views

What is steady state current?

I am currently trying to understand the following paper: On the nonlinear electromagnetic coupling between a coil and an oscillating magnet http://iopscience....
1
vote
1answer
1k views

Diffusion and Drift currents in forward bias

Why do the current in diode in forward bias configuration called "Diffusion current" even if this current is a resultant of external voltage supply which create electric field in diode ,hence should ...
1
vote
1answer
47 views

Why doesn't voltage drop naturally as a charge moves through the circuit?

If we ignore circuits for a moment and just think about a fixed charge and a test charge in space, we know that if we release the test charge, its PE changes and KE changes such that PE + KE is ...
1
vote
0answers
204 views

LC circuit problem

I am currently working on a LC circuit problem where there were given this question that I couldn't understand which is : theoretically justify the shape of the curve (the spring curve) by ...
1
vote
0answers
57 views

Is this Thevinin equivalent of a voltage divider, correct?

Found the PDF version of The Art of Electronics (Horowitz and Hill) recently, and, having nothing better to do... I thought I'd give it a read. It wasn't long before I hit a wall (courtesy: my inept ...
1
vote
2answers
40 views

How is the loop law applicable when I connect a battery with an ideal copper wire?

We would have a potential rise but where is potential drop? Considering wire to be having negligible resistance.
1
vote
1answer
43 views

Voltage of Arcing electricity

In Star Wars, Count Dooku electrocutes both Anakin and Yoda at a distance of about 5m. Obviously this is not meant to be scientifically accurate as it is a fictional movie, but how much voltage would ...
1
vote
0answers
110 views

Relationship between voltage to a speaker and the resulting sound pressure generated

So a question, suppose V, voltage, is a function of time V(t). Lets suppose you are playing a song on a speaker, lets assume you know the songs tone for a channel 1 and channel 2 for all 0 I'm ...
1
vote
1answer
36 views

Voltage and current at Points Throughout a Circuit

In a series circuit an electric field is created between both terminals of the battery . Is the movement of charges in a wire affected by the position of those charges within that wire? , eg would the ...
1
vote
0answers
2k views

Which Direction does current flow?

Summary: To simplify, I made the voltage equal to difference in charge: V = Q1 - Q2. If you stack the voltage, current should flow counter-clockwise If you look at the individual charges, current ...
1
vote
0answers
98 views

Flyback transformer for fusor?

I've always wanted to construct a farnsworth nuclear fusor. I recently ordered a 3-6 volt to 400,000 volt flyback transformer, and was wondering if that could be used in a fusor setup
1
vote
0answers
57 views

Voltage produced in transformer

The voltage produced in the turns of the coil in a transformer is given by (Faradys law): $$\epsilon\left(t\right)=\text{n}\times\phi'\left(t\right)\space\left[\text{V}\right]\tag1$$ Where $\text{n}$...