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

learn more… | top users | synonyms

1
vote
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 ...
-1
votes
3answers
65 views

What is the voltage in this circuit? [closed]

Attached is an image of circuit diagram for which I was asked to calculate the voltage for. However, because of the lack of information provided I belive this is impossible. Am I correct?
0
votes
1answer
1k views

Will a bulb glow brighter if voltage is increased but current remains the same?

I understand that increasing voltage increases the energy given to each coulomb in the circuit, so in theory more energy given to a bulb should make a bulb glow brighter. But also if voltage is ...
0
votes
1answer
224 views

Is the number of turns in a loop part of the magnetic flux?

In all both my physics textbooks, the number of loops $N$ is left out of the equation for magnetic flux $\phi_B = \int_s \vec B \cdotp\hat n dA$ and only when calculating the Emf induced by an ...
0
votes
2answers
118 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
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 ...
0
votes
1answer
56 views

Is “applying a voltage” the same as “applying a potential” to an electrode?

From what I understand, voltage is the potential difference, but it seems like the terms are used interchangeably. This is confusing me because I am only just learning what these terms mean. I'm also ...
1
vote
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 ...
0
votes
1answer
24 views

Explanation to the flow of charge

I came across a really cool Cymatics video: There is one part in the video which is unclear to me. Please refer to the snapshot below taken at 05:15. I see the equipment being close to a Van de ...
4
votes
3answers
798 views

Why do Capacitor Inductor circuits Oscillate instead of reaching equilibrium?

When the capacitor is fully charged there is a potential difference between its poles and that creates a current. This current would create a magnetic field that is changing in the Inductor (because ...
1
vote
1answer
34 views

Did I calculate this voltage correctly?

I have just started to learn physics. Please forgive me if I am completely wrong or something, I have just turned 14 haha. I am trying to learn about how to work out voltage for my year 10 exams. ...
1
vote
0answers
51 views

When a coil makes a complete turn, why is does magnetic flux double with respect to time?

EMF, $\mathcal{E}$, is equal to -d($\phi$)/dt Where $\phi$ is magnetic flux. Why is it that if from $t_1$ to $t_2$ the coil makes a complete turn and during this turn the normal vector's angle with ...
1
vote
3answers
224 views

Does KV in rc motors (RPM/Volt) tell us anything about the torque?

Considering that KV is RPM/Volt, does it ever tell us anything about the torque? Wouldn't you need to be told the torque separate from the KV rating? If torque can be derived from a KV rating then ...
1
vote
1answer
52 views

Thevenin theorem

Hi i got the trouble and i miss the concept about v out in thevenin i have the circuit like this so i used voltage divider for finding the voltage at point 1, but how to finding voltage at Vo , ...
0
votes
1answer
60 views

What is voltage in a circuit?

What is voltage in a circuit? We just started learning about electricity in my school. From what I understand; potential is potential energy per Coulomb and voltage means difference in potential. So, ...
0
votes
1answer
54 views

Deriving Loop Equations in a Circuit with 2 batteries?

First time posting here, so please help with formatting. I need help deriving loop equations for this becaue the 2 batteries/power supplies are throwing me off. https://i.imgur.com/MJH6mIM.jpg The ...
1
vote
0answers
14 views

Generation of negative ions in air [duplicate]

What is the main physical mechanism behind the generation of negative ions in air by a high negative voltage electrode ?
0
votes
0answers
71 views

Physical intuition behind the fact that current in an inductor lags behind the emf/voltage by $\frac{\pi}{2}$ in an AC circuit

What exactly is the reason that current through an inductor in an AC circuit acquires maximum value after quarter a time period ($\frac{T}{4}$) of the emf getting the max value?
0
votes
0answers
68 views

Do I Understand Voltage?

Below is a formula involving voltage and potential energy. $$\Delta U = q \Delta V$$ I would like to know if I understand it: If $\Delta V$ is positive, then the charge $q$ has moved from a lower ...
1
vote
2answers
86 views

Which expression to use for electrical power?

We know that electric power can be written as $P=VI$, or $P=\frac{V^2}{R}$, or $P=I^2R$. But when to use which one? Sometimes two different formulas give different results! Please explain with ...
0
votes
1answer
42 views

What is general strategy to find the resistance of medium?

What is general strategy to find the resistance of medium? These are some of the examples Two metal balls of the same radius $a$ are located in a homogeneous poorly conducting medium with ...
0
votes
1answer
42 views
68
votes
6answers
9k views

Why does public mains power use 50-60 Hz and 100-240 V?

Is there a physical reason behind the frequency and voltage in the mains electricity? I do not want to know why exactly a certain value was chosen; I am rather interested to know why that range/order ...
0
votes
1answer
263 views

Induced emf vs Potential difference

Let a square conductor frame length l, resistance R,be pulled out with a constant velocity v from a magnetic field B perpendicular to plane of the frame .Then an emf e=Blv is produced across the ...
0
votes
1answer
57 views

Voltage Circuit

I feel that I don't understand how voltage works in a circuit. I understand voltage to be electric potential energy per unit charge (kq/r). In the case of a circuit, electrons flow from low potential ...
1
vote
2answers
3k views

Why do voltmeters and ammeters have high and low resistance respectively?

I understand why voltmeters are connected in parallel and ammeters are connected in series, but why is it that to measure voltage, you must have high resistance, and to measure current, you must have ...
1
vote
2answers
74 views

Current due to External Electric Field

Assume a conductor in a rectangle shape for simplicity. Now, if I only choose one side of this rectangle having length L, and apply external electrical field ∑ only to it(along with the wire), what ...
1
vote
2answers
83 views

Units of the derivative of a function

I have a function $\phi(\mu, \sigma)$. $\mu$ and $\sigma$ are voltages (in mV in my case), so $\phi$ is a function of two voltages. $\phi$ itself, however, is in units of time (ms in my case). ...
0
votes
0answers
62 views

How to measure the static electricity voltage?

Some of the Wimshurst machine producers claim their machines produce about 70 000 volts. I wonder how to measure this value. How is it possible to measure the static electricity voltage?
0
votes
3answers
155 views

What is voltage?

I am a little unclear on what voltage actually is and I am trying to find out what the physical cause for voltage is. Is it the speed of the electrons through the conductor or is it an excess of ...
0
votes
2answers
109 views

Does a switched on power socket consume electricity? [closed]

Lets say I have a TV and a power socket but the TV switch is off however the socket switch is switched on, so will it consume electricity?
0
votes
0answers
45 views

I need some clarification about my understanding of voltages and resistance

So I was reading through this question, and I think resolved my query about what voltage actually is. I don't understand what we really mean by voltage drop But I just want further clarification ...
0
votes
0answers
28 views

Change in magnetic field region reduces overall voltage due to change in resistance?

Consider the following diagrams: Diagram(1): A large conductive slab($C$) with resistance ($R$) and region with magnetic field($B$), the conductor moves to the right as indicated with ($v$). ...
0
votes
1answer
267 views

relationship between voltage and current

I know that this question had been asked many times but I think it will be a new info in Ohm’s law: $$R = V/I$$ So Voltage is directly proportional to Current In Electric Power’s law: $$P = ...
0
votes
0answers
21 views

Voltmeter across two loops

If one terminal of a voltmeter is connected to a closed loop with current and the other to an open loop, will there be a reading? Theoretically, there is a potential difference across the terminals, ...
1
vote
0answers
15 views

Could a Kelvin Probe Force Microscope, in principal, be used as a voltmeter?

This question goes into the very nature of the work function that the Kelvin Probe Force Microscope (KPFM) measures. https://en.wikipedia.org/wiki/Kelvin_probe_force_microscope Let's say, you have a ...
0
votes
1answer
46 views

Voltage of a quadrupole magnet

I have a simple question and it's my first one in this community. :) Does the voltage of a quadrupole magnet depend on the power of the electron beam in a synchrotron? Perhaps someone has a good ...
1
vote
2answers
347 views

Which power equation to use: $P = I^2 * R$ or $P = V^2 / R$?

Given are ideal max voltage $V = 200\;\mathrm{V}$ and max current $I = 5\;\mathrm{A}$. Therefore: ideal resistance is $$R = \frac VI = \frac{200 \;\mathrm{V}}{5\;\mathrm{A}} = 40 ...
1
vote
2answers
3k views

How can be the neutral wire at 0 volts when current flowing through it?

Voltage is potential difference, and current flows because of voltage. So if the voltage is zero, how can current flow through the neutral wire.
0
votes
0answers
69 views

Current flow direction, based off the equipotential line?

From the following diagram: Given the wires are only connected to a certain portion of the conductor, will current flow all around the conductor? Or only throughout the equipotential line(diagram ...
0
votes
1answer
21 views

Does doping and size determine the characteristics of a semi-conductor?

Does the maximum voltage and current that a semiconductor can withstand (without being damaged) depend upon the size and doping of the semiconductor? If so, then please explain, 1.What is the reason ...
1
vote
4answers
219 views

Voltage - Energy drop

I'm having a hard time understanding the nature of voltage and am hoping you guys can help. The main issue is the concept of the voltage drop. Take the following circuits : In regard to the first, ...
0
votes
1answer
122 views

Difference in induced current, when magnetic field “span” is reduced?

A conductor of known volume $(V)$ passes a uniform magnetic field$(B)$with a constant velocity $(v)$ the conductor is a source of induced EMF, a power source to a circuit. The induced EMF can be ...
0
votes
1answer
74 views

What happens if I have a square conducting wire being permeated by a magnetic field and the field suddenly disappears?

Suppose there is a square conducting wire in a magnetic field. The two vertical branches will have the same emf, and the two horizontal branches will have 0 emf, resulting in a net emf of zero and ...
0
votes
1answer
208 views

Can electromagnets repel?

So I saw a video here https://www.youtube.com/watch?v=wzXRFp0DDrU (See the full video first) I don't understand that how is the electromagnet repelling things in the second half of the video? Also ...
0
votes
2answers
40 views

Is this diagram in my textbook not constructed to scale?

Or am I having an illusion. Clearly, the distance from 6v to 4v is not the same as 4v to 2v. I know it should be based on: $V = k\frac{q}{r}$.
0
votes
4answers
819 views

How power lines use high voltages with a low current?

I've read that power lines use high voltages and low currents to reduce power loss due to resistance. Looking at the formula for power - P = VI So to increase P, you increase V rather than I for ...
8
votes
5answers
5k views

How can one derive the Ohm's Law?

I am looking for the derivation of the Ohm's Law i.e., V is directly proportional to I. Can someone help me with it?
0
votes
2answers
190 views

Induced EMF, additive to conductor's closed circuit?

Assume the following conductor, with current flowing, powered from a source $S$: Now, I've introduced a magnetic field($B) to the conductor covering a small area of it like so: The change in ...
0
votes
1answer
212 views

Grounding a capacitor

When one of the plates of an isolated capacitor is grounded, does the charge become zero on that plate or just the charge on the outer surface become zero?