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

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Voltage across a resistors

When i was doing the practice problems, I found the following problem: I was able to solve for everything except for V4. When I looked at the solution manual,solution was as follows: Use KVL: V4 = ...
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0answers
24 views

Data acquisition from Pins ( 5Volt) [closed]

I'm trying to creat a data acquisition system using: computer Geosig ve-53 KPci3101 from the seismic sensor's manual we can see that every pin's output is a 5 volt (or 10?), my question is, how ...
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2answers
61 views

Solving for node voltages

I have the following circuit and i need to solve Is, v1 and v2. First of all, I assumed that this problem will involve supernode principle since there is a voltage source between V1 and V2. Then, i ...
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3answers
4k views

Is voltage important when creating a magnetic field?

Would a DC circuit that has a high current and low voltage have a powerful magnetic field? I'm trying to create a powerful solenoid. In order to create a powerful magnetic field, I'm focusing more on ...
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2answers
67 views

Touching one end of a battery

What happens when I touch one end of a battery? Is there any flow of charge from the battery to my body? I know that connecting a battery to both ends of capacitor causes the charge from one plate ...
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92 views

Accelerating potential

Will an accelerating potential accelerate a neutral atom? For example, consider an atom of hydrogen subjected to an accelerating potential of $V$. As the kinetic energy of a particle accelerated by a ...
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1answer
46 views

Why is resistance $U/I$ rather than $I/U$?

What is the difference between resistance and conductance and why is resistance $U/I$ and not $I/U$? (I know $I/U$ is conductance.) But I don't see the difference between both.
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1answer
47 views

Why does a variable potential divider have the ability to reduce current through a component to zero

For example, the diagram in my text book: shows a filament lamp, in series with a uniform resistive wire, which can have its voltage and current varied by moving the sliding contact, e.g., a ...
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1answer
92 views

How is a potential divider able to reduce current to zero?

For example, a filament lamp, in series with a uniform resistive wire, can have its voltage varied by moving the sliding contact, e.g., a rotatable wheel. However, why is a potential divider able to ...
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16 views

How to calculate ion lithium battery voltage?

I have raw data from cyclic voltammetry test of ion-lithium battery. But I need nominal voltage or Open Circuit Voltge (OCV), like is reported in the literature. But I only have Voltage (V) vs ...
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2answers
95 views

What exactly is potential difference? What are the factors that effect it?

I am asking this question because at first I thought that this concept was pretty clear to me, but it is not. So, my first question: Is potential difference only a property of an electric field? If ...
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2answers
179 views

Transformers: relation between their current, voltage and resistance

My current understanding Transformers are used to step up and down voltage keeping power constant. Hence, for example, if I step up some voltage, the current will decrease in the secondary circuit. ...
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1answer
45 views

$P=V^2/R$ confusion

I am confused on how to apply the formula $P=\frac{V^2}{R}$ If I am given a bulb say with power 60W and it is connected to a supply of 120V. Then the resistance of the bulb is 240$\Omega$ but if ...
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5answers
12k views

Why is electric potential scalar?

I can't conceptually visualize why it would be so. Say you have two point charges of equal charge and a point right in the middle of them. The potential of that charge, mathematically, is proportional ...
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0answers
36 views

How to control a dc motor? [closed]

I am in 8th standard and I am doing a project on 3d printing pens. I want to know how to control a dc motor, so that when I press a button it should increase its speed gradually till it reaches its ...
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2answers
140 views

Understanding parallel plate capacitors [closed]

I need help with understanding this assignment. I originally though of using the equation of Eo*A/D = Q/ΔV but I don't know how to answer this without actual numbers to plug in besides the epsilon-not ...
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2answers
345 views

Should the electric potential of a positively charged sphere be negative?

Because the indefinite integral of the electric field results in a negative value? (As the function is proportional to $r^{-2}$? I've got to be missing something... Help please!! Thanks! Also, I ...
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0answers
42 views

Determining initial voltage across a capacitor [closed]

This one has got me stumped. I have a graph of voltage vs time and a corresponding power vs time graph. Taking the integral of the power vs time graph gives me the work done on the capacitor. Now the ...
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0answers
41 views

Voltage wave reflections in transmission line loaded by matched resistor

Suppose I have a power source, a transmission line and a resistive load all connected together and all sharing the same impedance. If I send a voltage pulse starting at the power source, traveling ...
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1answer
18 views

Build a device that can set voltage according to intensity of the light shined [closed]

I want to build a device that uses photodiodes and photoresistors to set the voltage in the circuit that shines a bulb. The idea is simple. When the light is intense, the bulb should shine less, when ...
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4answers
1k views

If induced voltage (back-emf) is equal and opposite to applied voltage, what drives the current?

Suppose we have a circuit with a voltage source, a switch open and an inductor all in series. If we close the switch, the potential difference of the voltage source is instantaneously applied to the ...
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3answers
129 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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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 ...
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2answers
99 views

Kirchoff's rules and inductance

Can Kirchoff's loop rule be applied in a scenario involving an inductor? Kirchoff's loop rule states that the closed loop integral of E dot dl is equal to zero. But, in a situation with an inductor, a ...
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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
2k views

A confusion in ohms law $V = IR$

ohms law clearly states that potential difference is directly proportional to the current flowing through the wire or V directly proportional to I ______(i) so the formula which is ...
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3answers
633 views

Should the term Watt's Law be used for $P = IV$?

I'm revising some electrical curriculum for a technical training program. In the curriculum students have to calculate values using Ohm's law and the equation $$\text{Power = Current * Voltage}$$ ...
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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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0answers
19 views

How polarized object's polarized atoms behaves like charge?

Electrical polarization is just the shifting of the constituent atoms' protons and electrons in opposite directions. This creates a bound charge, and this bound charge creates voltage and thus an ...
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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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0answers
27 views

Modeling the working of a transformer by pushing magnet into a coil

Let me go step-by-step. First I will outline a simple transformer. There are two circuits next to each other (not touching). One is an electromagnet set-up (with AC supply) and the other has a ...
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1answer
65 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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1answer
56 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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105 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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2answers
774 views

Electric power for current density

The electric power produced by a current $I\in\mathbb{R}^+$ and a voltage $V\in\mathbb{R}^+$ is $$ P = IV. $$ Now the current is given as an (alternating) current density $J(\mathbf{x},t)=\Im(e^{i\...
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2answers
82 views

Voltage and Current in an Electromagnet

I'm having a little bit of trouble with electromagnets. I know that a magnetic field is induced by current flowing through a conductor, but what role does voltage play? Does it have an effect on the ...
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0answers
39 views

What were the experiments performed that lead to ohm's Law

How was the relationship of $V=IR$ first developed? What were the experiments that were preformed that lead to Ohm's Law? I understand that they had devices during George Ohm's time to measure current ...
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0answers
26 views

Fréedericksz transition question

What is the lowest voltage needed for a Fréedericksz transition to occur?
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0answers
41 views

High voltage arc stability reasons (in some cases shape of the arc is rapidly changing)

When turning off 500kV switch we can see an arc like on this picture this arc is very unstable, curved, distorted. It consists of many little loops. While on this picture electric arc patiently goes ...
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2answers
739 views

Does voltage drop occur with zero load and zero resistance [duplicate]

Imagine a circuit consisting of just a battery and conducting wires which have zero dissipativity so that there is no loss of energy( Zero resistance). If the wires are connected to both terminals the ...
0
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1answer
91 views

How to draw + and - and $\nabla \times E$ on a circular wire?

Faraday's Law: $$\vec{\nabla}\times\vec{E}=-\frac{\partial\vec{B}}{\partial t}$$ Circulation of electric field: For time-varying magnetic field and a closed wire, How can we add + and - pole ...
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4answers
137 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
38 views

Induced EMF dependent on terminal wire connection?

Figure(a): When a conductor moving inside magnetic field, of a given length at a certain velocity the induced EMF is: $$\epsilon = vBL$$ However, what if we changed the position where the bottom ...
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1answer
84 views

How to calculate resistivity of ring [closed]

Q: In a resistance experiment, a gold ring was connected into a circuit as a resistor. The connections touched on diametrically opposite points on the circular ring. Its diameter is 2cm, and the ...
0
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1answer
58 views

Voltage and Energy in a capacitor [duplicate]

Well, my first question is related to the energy of the capacitor. Why does the energy of capacitor equals $E=\frac{1}{2}QV$ and not $E=QV$;in other words, why we multiplied it by $\frac{1}{2}$?? My ...
0
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4answers
78 views

Resistor and voltage drop [duplicate]

I know that a voltage drop of a resistor is the energy lost from the potential energy of the electrons.well, what i am really confused about is why the potential energy of the electron decreases as it ...
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2answers
96 views

Does voltage always cause current?

I'm wondering if the following statement is fully correct: Voltage causes current through a closed circuit, but through an inductor it is the change in current that causes a voltage. Obviously ...
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1answer
47 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
117 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 ...