Electric field Definition and 1000 Threads

An electric field (sometimes E-field) is the physical field that surrounds electrically-charged particles and exerts force on all other charged particles in the field, either attracting or repelling them. It also refers to the physical field for a system of charged particles. Electric fields originate from electric charges, or from time-varying magnetic fields. Electric fields and magnetic fields are both manifestations of the electromagnetic force, one of the four fundamental forces (or interactions) of nature.
Electric fields are important in many areas of physics, and are exploited practically in electrical technology. In atomic physics and chemistry, for instance, the electric field is the attractive force holding the atomic nucleus and electrons together in atoms. It is also the force responsible for chemical bonding between atoms that result in molecules.
Other applications of electric fields include motion detection via electric field proximity sensing and an increasing number of diagnostic and therapeutic medical uses.
The electric field is defined mathematically as a vector field that associates to each point in space the (electrostatic or Coulomb) force per unit of charge exerted on an infinitesimal positive test charge at rest at that point. The derived SI units for the electric field are volts per meter (V/m), exactly equivalent to newtons per coulomb (N/C).

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  1. Iron_Man_123

    Is the force on a dipole parallel or perpendicular to the electric field?

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  2. Cocoleia

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  3. Cocoleia

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  4. Arman777

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  5. C

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  6. Cocoleia

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  7. T

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  8. P

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  9. M

    Difference Electric Field Strength Point Charges vs. Plates

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  10. Iron_Man_123

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  11. L

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  12. Arman777

    Why electric field between two plates ##\frac {σ} {ε_0}## ?

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  13. Vanessa Avila

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  14. J

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  15. J

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  16. Mason Smith

    Find the magnitude of the electric field at regions 2 and 3.

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  17. Cocoleia

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  18. grandpa2390

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  19. jlmccart03

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  20. R

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  21. J

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  22. R

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  23. tarkin

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  24. P

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  25. doktorwho

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  26. ThunderLight

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  27. J

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  28. Iftekhar Uddin

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  29. Mason Smith

    How do I find the points where the electric field is zero?

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  30. A

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  31. jlmccart03

    Find electric field strength expression for a specfic region

    Homework Statement A thick, spherical shell of inner radius a and outer radius b carries a uniform volume charge density ρ. Find an expression for the electric field strength in the region a<r<b. Homework Equations Gauss's Law ∫E⋅dA Area of a sphere The Attempt at a Solution I know I am...
  32. jlmccart03

    Electric field strength near a metal plate

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  33. jlmccart03

    Magnitude of electric field near spherical shell

    Homework Statement A 10-nC point charge is located at the center of a thin spherical shell of radius 8.0 cm carrying -20 nC distributed uniformly over its surface. What is the magnitude of the electric field 2.0 cm from the point charge? Homework Equations E = kq1q2/r^2 The Attempt at a...
  34. J

    Gaussian Shell and net electric field

    Homework Statement Homework Equations σ=q/(4πr^2)→q=σ(4πr^2) E=q/(4πEod^2) E=(4πr^2σ)/(4πEod^2)The Attempt at a Solution So the first thing that i could include was that the point p was inside Shell 1 and therefor would not be affected by Shell 1. So it should be a fairly simple plug in the...
  35. J

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    Homework Statement The problem statement is in the attachment Homework Equations E[/B] = -∇φ ∇ = (∂φ/∂r)er The Attempt at a Solution I am confused about how to do the derivative apparently because the way I do it gives E = - (∂[p*r/4πε0r3]/∂r)er = 3*(p*r)/4πε0r4er
  36. J

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  37. L

    Coulomb's Law problem: Charged particles and the net electric field and force

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  38. S

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  39. Ryan Sandoval

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  40. J

    Calculating Net Electric Field for a Charged Arc

    Homework Statement Homework Equations L=pi*r/2 λ=q/L Enet=∑λ(2sinθ)*kThe Attempt at a Solution So first to calculate L for each arc L1=pi(.107m)/2 L2=pi(.214m)/2 L3=pi(.321m)/2 and lambda: λ1=3.3E-6/L1=2E-5 λ2=-12E-6/L2=-3.9E-5 λ3=29.7E-6/L3=5.9E-5 So using θ=pi/2 and rearranging the...
  41. F

    An electric charge feels its own self electric field

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  42. J

    Calculating Electric Field Using Coulomb's Law

    Homework Statement Homework Equations Ex=1/k*1/(a^2/2)*1/(sqrt2)*cos(theta)*(sum of charges) Ey=1/k*1/(a^2/2)*1/(sqrt2)*sin(theta)*(sum of charges) The Attempt at a Solution So first off I can see that I don't need to calculate the force in the x direction as each q cancels out when...
  43. jlmccart03

    Find the electric field on a proton by an electron

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  44. jlmccart03

    Find the electric field at x and y coordinates?

    Homework Statement A 60 μC point charge is at the origin. Find the electric field at the point x1 = 50 cm , y1 = 0. Homework Equations Coulombs Law: F = (kQ1Q2)/r2 Electric Field: E = kQ/r2 k = 8.99*109 C The Attempt at a Solution So taking Coulombs Law and deriving the Electric Field...
  45. Cocoleia

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  46. E

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  47. DoubleE7

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  48. U

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  49. P

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  50. B

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