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

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Power formulas? [duplicate]

Are different power formulas in circuits used for different reasons? For Example Power = V^2/R Power = I^2/R Power = VI
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0answers
16 views

Electronics - Series/Parallel Circuit Question [on hold]

Im working on this question but I've confused myself more by watching videos. I'm not sure if the circuit is in series and parallel or just parallel. I understand the 2.5k Ohms and 1.4k Ohms are in ...
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1answer
21 views

If a battery is open on one end but connected on the other, does it raise the potential on the connected end?

If a battery has one end open and other end connected to a circuit will the battery increase the potential at the point of connection?
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1answer
61 views

What do the batteries actually do to the electrons?

I am plagued by this simple question that what force exactly causes the motion of an electron in the middle of a lattice of electrons of a wire? a. Is it an electric field created inside a wire due to ...
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2answers
57 views

Why does internal resistance increase as current decreases?

Our class conducted and experiment to investigate internal resistance and terminal pd, using a cell, fixed resistor and variable resistor. The results were as follows: As the resistance of the ...
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2answers
155 views

Does charge of a metal charged by induction determine by which ends of the metal is grounded to?

Does charge of a metal charged by induction determine by which part of the metal is ground to? I draw a diagram to make it simple to understand: Right diagram: When ground is touched with the ...
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4answers
191 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, ...
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2answers
49 views

How do we get 25kV at power stations? [on hold]

Could anyone tell how we get a potential difference of 25000v at power stations? Is it due to the number of electrons present or the speed of the turbine or the large induced emf generated by the ...
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0answers
17 views
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3answers
2k views

How is a potential difference created between two points?

I would like to know how potential difference is created between two points?Is potential difference created by adding more electrons at one side?If that's the case how to add more electrons at one ...
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3answers
84 views

Why is $\text{R}$ resistance in $\text{V=IR}$? [on hold]

Today I studied about Ohm's law which states- The current through a conductor between two points is directly proportional to the voltage across the two points.By introducing constant of ...
23
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13answers
66k views

I don't understand what we really mean by voltage drop

This post is my best effort to seek assistance on a topic which is quite vague to me, so that I am struggling to formulate my questions. I hope that someone will be able to figure out what it is I'm ...
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5answers
635 views

Why is there a potential difference?

The question then asks for the potential difference between $X$ and $Y$, which is claimed to be $3.6\text{ volts}%$. Why would there be a potential difference in this case? If I connect a lightbulb ...
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1answer
44 views

What is the difference between the potential difference and potential energy of an electron?

What is the difference between the potential difference and potential energy of an electron? Let's take an example the potential difference (PD) across a resistor. if there's a current flowing, the ...
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1answer
30 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, ...
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1answer
19 views

Does a charge difference necessitate a potential difference?

Consider two metal objects, X and Y that when connected by a conducting wire results in a transfer of electrons from Y to X. What can be concluded about X and Y before the connection was made: ...
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2answers
324 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 ...
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1answer
177 views

Current and Resistance-Effects of the Length of the Wire

Two wires of the same material are both connected to a 9-V ideal battery. They have the same cross section area but wire 2 is twice longer than wire 1. Compare the following quantities by answering ...
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2answers
333 views

How does back-emf oppose the input-current?

A circuit, has current $A$ flowing at a certain $V$. When there is a change in magnetic-flux, based on Faraday's law of induction & Lenz's law, we know that there is change in Potential ...
3
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2answers
632 views

If I charge a battery using a much higher current, can it explode?

If I have a 12V 4Ah lead acid battery and use a battery charger that, let's say for example, can charge 10A, 50A, or 100A. If I theoretically turned it to 100A will the battery explode? I understand ...
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3answers
64 views

What does earthing do in electrostatics?

What does earthing actually do in electrostatics? As far as i know, it simply sets the potential of the object that is earthed to zero. To explain my question further with an example, consider this ...
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0answers
39 views

Best Piezoelectric crystal [closed]

Which piezoelectric crystal produces the maximum voltage?
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2answers
2k 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 ...
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2answers
41 views

Potential Energy of Point Charges in a Square [closed]

So, an AP Prep book for the Physics 2 test has the following problem: My reasoning is as follows: The total potential energy = the sum of the PE of each of the 4 charges Which will equal 4x the PE ...
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1answer
123 views

Back EMF & Current, how can we make the current $I$ stable?

Lets assume we have a wire that has $10V$ across and $1$ $Amp$ flowing, now if this conductor is introduced to a changing magnetic field, $-EMF$ is induced, can we control our voltage to increase it ...
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2answers
3k views

Why does voltage change in series circuit but not in parallel circuit?

Voltage divides after every resistor in series but not when placed in parallel. Please explain this with using very less or no mathematical equations. I have tried searching for an answer online but ...
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1answer
217 views

Measured voltage on coil

I have a simple circuit of coil with inductance L $$u_c(t)= -L\frac{di}{dt}$$ and AC source with output voltage $u_s$ What is actually measured by the voltmeter ($u_c$, $u_s$ or $u_s - u_c$)? If ...
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1answer
34 views

Voltage homogeneity across cell membrane

During respiration, individual cells produce a relatively large potential difference ($\sim 100$ mV) between the inside and outside, using energy to pump $H^+$ out of the cell to the liquid ...
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4answers
57 views

Electrons moving in a simple circuit with a battery and a light bulb

I believe my understanding of electric currents is flawed and want some help to clear up a few things. I'm not looking for a precise scientific understanding, but to understand the basics. I'll try to ...
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3answers
154 views

How does voltage divided by EMF show efficiency?

I get that electromotoric force (emf) is energy per coulomb supplied and that voltage is energy per coulomb used but I don't get what it means when we say that the voltage divided by the emf gives the ...
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0answers
25 views

What exactly is Breakdown Voltage of Air?

Most of the online sources say that the breakdown voltage of air is 30kV/cm. I've made a Cockcroft Walton multiplier and I can see the air breaking in between 17-18kV/cm. Only in a discussion at one ...
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2answers
42 views

Series circuit of capacitor and ohmic resistance: Voltage drop at Capacitor? [closed]

I have a question to an exercise I am currently trying to solve. It is given an Capacitor and an ohmic resistance in a series circuit. The whole voltage is 40V, the resistor has an resistance of ...
3
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3answers
31k views

Using A.C or D.C to create an electromagnet

Does it matter if I use A.C or D.C as a source to create an electromagnet? Or Does it depend on the voltage of current? For example: I have a coil which has about 50 turns. If I use same amount of ...
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2answers
51 views

How does increasing the distance between 2 copper plates in a circuit affect the capacitance? [duplicate]

We have been told that the voltage decreases, but not been given a proper explanation by my teacher. Can anyone shed some light on this? Also, does increasing the distance between the plates of a ...
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1answer
39 views

Link between potential difference and voltage

Voltage in a radial electric field is given by kQ/r (where k=1/(4*pi*epsilom.0)). Voltage in a circuit is given by IR, so if R=0 there is no change in voltage for an electron flowing through the ...
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21 views

Plot current-voltage curve

I have been given the following question as part of an investigation for my Applied Maths course: "[...] Then construct the current-voltage curve, i.e. the dependence of $\left< \dot{\theta} ...
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3answers
29k views

Current without Voltage and Voltage without Current?

At school I've always learned that you can view Current and Voltage like this: The current is the flow of charge per second and the Voltage is how badly the current 'wants' to flow. But I'm having ...
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24 views

Logarithm of the voltage of the inductor in RL circuit experiment is nonlinear with time

I performed an experiment about the RL circuit, with following circuit: (I used the PASCO RLC circuit lab.) By Kirchhoff's voltage law, (denoting the emf of the signal generator $\mathscr E$, ...
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2answers
50 views

If Electric field is constant in a region, does it imply potential is also constant?

I am a bit confused about these concepts- when is electric field or electric potential constant so i would appreciate if anyone could brief me about these things as well. Here i am referring to ...
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4answers
29 views

Is impedance the ratio of voltage to current at any instant?

My book defines impedance as the ratio between the amplitude of voltage to that of the current (Vmax to Imax), I just wanted to make sure whether its also true for the instantaneous values of voltage ...
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1answer
22 views

High Voltage Powerlines - clarification of energy loss

I've been having a bit of trouble understanding the High-Voltage powerlines. If I was sending power from $A \rightarrow B$, we have: Ohm's law $V = IR$ Power lost in the form of heat $P = I^2 R$ ...
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4answers
75 views

Relationship among heat generated, power, current and voltage

Can you help me understand the relationship between current, voltage and heat generated? I tried two sets of heated gloves. One uses a battery which generates 7.4 volts x 2 amperes (14.8 watts of ...
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0answers
22 views

Accelerating voltage relationship to energy

if I have the accelerating voltage, how can I obtain the energy in eV? Basically, I asked someone for the energy, but instead they gave me the accelerating voltage. What more data would I need to ...
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1answer
11 views

grounding spherical shells

a Q1 charged spherical shell A with radius of a is inside a Q2 charged spherical shell B with radius b. now A is grounded. since no force is acting on Q1 all of them should be neutralized. and at the ...
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1answer
23 views

Ohm's law deviation

In terms of superconductivities and diodes (I do not know amything else except these), Ohm's law deviate from a linear relation. I search many titles or tags for this but I did not understand properly ...
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1answer
39 views

Potential Dividers - Why do I need the second resistor?

So I am doing the OCR Physics GCSE course, and I have just learnt about potential dividers in electronic circuits. I get that the first resistor steps down the voltage so a component with a lower ...
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1answer
150 views

Spherical magnet inside a solenoid

When passing a bar magnet through a long solenoid why is it that the induced emf when the magnet is in the middle of the solenoid is zero? And if a spherical magnet is put inside the solenoid, will ...
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3answers
50 views

Potential Difference Across Components in Parallel & Series Circuits

So I have two questions, but they're kind of linked so I'm putting them in one. 1) I have a simple circuit with a battery connected to three lamps in series. If I then add a second battery but ...
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3answers
1k views

Measuring voltage drop from induced current

I'm having trouble connecting voltage drops and induced current. Imagine you have a triangular loop make up off three resistors. You place this loop in a constantly changing magnetic field. This ...
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0answers
37 views

Wind turbine design question [closed]

I am planning to design a wind turbine that is has rotor blade radius of 0.915m and is connected to a generator. The generators specifications are, it is an ac generator with 5000 coil turnings and a ...