What is Electrical potential: Definition and 113 Discussions

The electric potential (also called the electric field potential, potential drop, the electrostatic potential) is the amount of work energy needed to move a unit of electric charge from a reference point to the specific point in an electric field with negligible acceleration of the test charge to avoid producing kinetic energy or radiation by test charge. Typically, the reference point is the Earth or a point at infinity, although any point can be used. More precisely it is the energy per unit charge for a small test charge that does not disturb significantly the field and the charge distribution producing the field under consideration.
In classical electrostatics, the electrostatic field is a vector quantity which is expressed as the gradient of the electrostatic potential, which is a scalar quantity denoted by V or occasionally φ, equal to the electric potential energy of any charged particle at any location (measured in joules) divided by the charge of that particle (measured in coulombs). By dividing out the charge on the particle a quotient is obtained that is a property of the electric field itself. In short, electric potential is the electric potential energy per unit charge.
This value can be calculated in either a static (time-invariant) or a dynamic (varying with time) electric field at a specific time in units of joules per coulomb (J⋅C−1), or volts (V). The electric potential at infinity is assumed to be zero.
In electrodynamics, when time-varying fields are present, the electric field cannot be expressed only in terms of a scalar potential. Instead, the electric field can be expressed in terms of both the scalar electric potential and the magnetic vector potential. The electric potential and the magnetic vector potential together form a four vector, so that the two kinds of potential are mixed under Lorentz transformations.
Practically, electric potential is always a continuous function in space; Otherwise, the spatial derivative of it will yield a field with infinite magnitude, which is practically impossible. Even an idealized point charge has 1 ⁄ r potential, which is continuous everywhere except the origin. The electric field is not continuous across an idealized surface charge, but it is not infinite at any point. Therefore, the electric potential is continuous across an idealized surface charge. An idealized linear charge has ln(r) potential, which is continuous everywhere except on the linear charge.

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  1. V

    Confusing definition of electrical potential energy

    If the book had said that electrical potential energy is the negative of work done by electrical force on a charge, then the definition would be very clear and easy to understand. So, why should the book give this confusing definition instead.
  2. F

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  3. Adams2020

    Mass difference due to electrical potential energy

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  4. cwill53

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  5. iochoa2016

    Understanding Electrical Potential Energy of a charge distribution

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  6. L

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  7. T

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  8. K

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  9. currently

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  10. C

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  11. R

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  12. SebastianRM

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    So I have been wondering: The potential for a point charge at the origin, is described as: (Using the reference point at infinity): V=1/(4πε) * q/r My question is, what happens to this Potential the closer we are to the point charge, and so the closer we would get, the Potential seems to go...
  13. HotFurnace

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  14. N

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  15. icesalmon

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    Homework Statement From Griffiths Third Edition: "Introduction to Electrodynamics" p.p. 81 ex. 2.6 "Find the potential inside and outside a spherical shell of radius R, which carries a uniform surface charge. Set the reference point at infinity. Homework Equations V(r) = -∫E⋅dl The...
  16. B

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  17. F

    Extrema of electrical potential

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  18. Y

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  19. A

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  20. A

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  21. jlmccart03

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  22. Nathan phisi

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  23. E

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  24. Haynes Kwon

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    Hi. Getting straight to the point, what is the difference between electrical potential energy and electric potential? Please be as specific as you can. Thank you.
  25. ikihi

    What is the electrical potential at point P?

    Homework Statement Three point charges of +6.00 μC, +4.00 [/B]μC, and +6.00 μC are placed along the x-axis 0.200 m above the +4.00 μC charge as shown in the figure below. What is the electrical potential at point P (relative to infinity) due to these charges? Diagram...
  26. L

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    In regards to voltage and electrical potential, I have a question. I understand the voltage to be the difference in electrical potential of two separate points. So in an analogy am I correct to compare this to a bowling ball being 4 feet off the ground. So the bowling ball has a gravitational...
  27. J

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    Assuming the resistance of a wire in a series circuit, consisting only of 1 component (e.g. filament lamp) and a battery, is negligible; does each Coulomb of charge commit all of its electrical potential energy, supplied by the battery's potential difference, as work done across the component...
  28. F

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    Homework Statement Two charged plate hold a charge of 3 coulombs with the upper plate being positively charged and the lower plate being negatively charged. They have a pd of 6 volts. There is a spacing of 20 cm between them. A positive charge q with a charge 0.4 coulomb is located at midpoint...
  29. Clara Chung

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  30. G

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    Why does the potential energy of a system of two charged particles decrease as the distance between them increases? It seems that the PE should increase, as in U=mgh; as h increases, the PE increases. Why does this not occur in electrical potential energy, and in the gravitational potential...
  31. JulienB

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  32. E

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  33. I

    Electrical potential of the sphere

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  34. gracy

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    Consider a system of two charges ## q_1## and ##q_2## separated by distance ##r_1##.This configuration is associated with a potential energy ##U_1##.When the separation is increased to ##r_2##.Potential energy becomes ##U_2## ##dW_E##=##\vec{F}##.##\vec{dr}##...
  35. N

    Graviational vs Electrical Potential

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  36. P

    Electrical Potential Energy of three quark system

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  37. A

    Why does the same current flow through resistors in series?

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  38. R

    Two charges, Electrical Potential

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  39. U

    Electrical Potential between 2 points

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  40. 2

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  41. D

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  42. M

    What is the relationship between electric potential and electric field?

    Q1: Use the graph (see attachment) to write the empirical equation V(r) for a charge cylindrical shell with appropriate constants, including units. Show all work. Q2: What is the interpretation of the horizontal axis intercept? Q3: What is the significance of the slope of the graph? I...
  43. P

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  44. A

    Electrical potential and potential difference

    Indian school books say -- We define the electrical p.d. between two points in an electrical circuit carrying some current as the work done to move a unit charge from one point to other! =>V=W/Q But, my doubt is...since work done is directly proportional to distance between two points...
  45. M

    Deriving electrical potential

    Hi. I have no idea how to do this. It's complicated because the length here is a variable. I posted the same question before but there was a little mistake so I am reposting this again. The picture below shows the potential due to ring charge. Please show the full steps of deriving the...
  46. L

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    The problem is to find the potential at a point that is 3 meters away from two charges. (one 3 meters above, and the other 3 meters below) q1=3μC q2=6μC I put that Ep=Epq1+Epq2 Epq1=K*q1/r1 Epq2=K*q2/r2 K=1/(4πε0)=8.988x109 This gives me: Epq1=8.988x109*(3x10-6/3)=8988J...
  47. G

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  48. Z

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  49. I

    Mathematical method in electrical potential ?

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  50. R

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    Homework Statement Charge of uniform density 4.50nC/m is distributed along the circle of radius R. What is the electrical potential (relative to zero at infinity) at the centre of the circle? Answer: 254V Homework Equations electric potential: V=kQ/r The Attempt at a Solution Because the...
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