What is Electrostatic: Definition and 879 Discussions

Electrostatics is a branch of physics that studies electric charges at rest.
Since classical physics, it has been known that some materials, such as amber, attract lightweight particles after rubbing. The Greek word for amber, ήλεκτρον, or electron, was thus the source of the word 'electricity'. Electrostatic phenomena arise from the forces that electric charges exert on each other. Such forces are described by Coulomb's law.
Even though electrostatically induced forces seem to be rather weak, some electrostatic forces such as the one between an electron and a proton, that together make up a hydrogen atom, is about 36 orders of magnitude stronger than the gravitational force acting between them.
There are many examples of electrostatic phenomena, from those as simple as the attraction of the plastic wrap to one's hand after it is removed from a package to the apparently spontaneous explosion of grain silos, the damage of electronic components during manufacturing, and photocopier & laser printer operation. Electrostatics involves the buildup of charge on the surface of objects due to contact with other surfaces. Although charge exchange happens whenever any two surfaces contact and separate, the effects of charge exchange are usually only noticed when at least one of the surfaces has a high resistance to electrical flow. This is because the charges that transfer are trapped there for a time long enough for their effects to be observed. These charges then remain on the object until they either bleed off to ground or are quickly neutralized by a discharge: e.g., the familiar phenomenon of a static "shock" is caused by the neutralization of charge built up in the body from contact with insulated surfaces.

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  1. KiNGGeexD

    Electrostatic fields- What defines an electrostatic field?

    I have a question about electrostatic fields! I was given these two equationsE= k [xy xˆ + 2yz yˆ + 3xz zˆ] E= k[y^2 xˆ+ (2xy+ z^2)+ 2yzzˆ] And asked to determine if either could be an electrostatic field, I'm not asking how to solve this problem but I'm not sure what defines an...
  2. D

    Shielding - Need to ground an electrostatic shield?

    Shielding -- Need to ground an electrostatic shield? I am reading this app note by analog devices: http://www.analog.com/static/imported-files/application_notes/41727248AN_347.pdf At the bottom of the first page it says: "An electrostatic shield, to be effective..." "But grounding the...
  3. C

    Do purely electrostatic ion traps exist?

    I was wondering whether you could trap a cation simply by putting it inside a positively charged sphere. Is this possible?
  4. E

    What factors could alter electrostatic force?

    While investigating Coulomb's Law, I created a graph of F-1/2 vs. r to display results. The gradient of this graph is much steeper than it should be. What factors could affect the electrostatic force to make this happen? Any suggestions would be greatly appreciated! (The experiment...
  5. D

    MHB Electrostatic Force: Effects of Distance

    How does electrostatic force vary between two objects if the distance is doubled? I know with gravitational force as the distance doubles the force decreases by \(\frac{1}{4}\).
  6. R

    Electrostatic demonstration

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  7. O

    Conductors in Electrostatic Equilibrium

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  8. vanhees71

    Massless charged particle in electrostatic field

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  9. D

    Solve Electrostatic Forces Homework: Tension & Charge

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  10. E

    How Long Does It Take to Discharge Body's Electrostatic Potential?

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  11. PsychonautQQ

    Electrostatics: Finding Equilibrium with Three Charges

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  12. A

    Voltage on a electrostatic charged sphere

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  13. D

    Electrostatic force, voltage, electrostatic potential

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  14. Y

    Charged conductor in electrostatic equilibrium

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  15. jacobi1

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  16. M

    Can Electrostatic Precipitation Improve Air Quality in a Homemade Clean Room?

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  17. kmm

    Electrostatic Boundary Conditions

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  18. B

    Electrostatic E Fields - Possible/Impossible

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  19. K

    REALLY easy electrostatic question

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  20. C

    N??Solving Electrostatic Fields Problems

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  21. K

    Simple electrostatic field question

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  22. M

    Electrostatic force between 2 hemispheres

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  23. R

    Some Qustions of Electrostatic Induction

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  24. H

    Reference Electrostatic Potential

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  25. S

    Electrostatic self-energy

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  26. B

    Principal Difference between electrostatic potntial and gravitational

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  27. J

    Finding Electric Fields and Electrostatic Potential

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  28. M

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  29. R

    What is this nature of Electrostatic Field ?

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  30. B

    Expression of electrostatic field

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  31. N

    Finding the magnitude of the electrostatic force from a thin rod

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  32. U

    Electric field strength and electrostatic potential

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  33. T

    What is the potential difference between two points in an electric field?

    Homework Statement A space probe travels towards a planet measuring the electrostaticpotential as it approches. the electric field strength is -500 N/C at the altitude of 600,000 KM and it decreases steadily until it reaches -400 N/C at 580,000 KM above the planet's surface . find the...
  34. M

    Electrostatic Field: Work Done by Electric Forces

    what is the work done by electric forces in moving a charge Q=1 nC from the origin to the point (1m, 1m, 1m) in the electrostatic field given by E=(x,y,z) = (x* (a sub x) + y^2*(a sub y) - (a sub z) V/m in the Cartesian coordinate system along the straight line joining two points?
  35. J

    About Electrostatic Potential and Electric Field

    How do I know if E (electric field) and \Phi (electrostatic potential) is continuous at the surface? I'm asking this because I have a problem choosing which formula to use, if you know what I mean. There are a lot of formulas for E and \Phi .
  36. P

    Is electric potential always continuous in an electrostatic field?

    Is electric potential always continuous in an electrostatic field? I mean, does it suffer from discontinuity at any point?
  37. B

    Is the charge induced on a conductor equal to or less than the inducing charge?

    electrostatic induction... when a conductor is charged by the method of induction,is its charge equal in magnitude to that of inducing charge or somewhat less?
  38. X

    Work done by electrostatic force. Positive or negative?

    Homework Statement A small, positively charged sphere is released from rest and moves directly away from a larger, positively charged sphere. During this process, the electrostatic force: a) does positive work and increases the kinetic energy of the small sphere b) does negative work and...
  39. X

    Finding minimum electrostatic energy

    Homework Statement There are 2 small metal balls of radius r1 and r2 and are kept at very large distance , what should be ratio of charges on them for electrostatic energy to be minimum Homework Equations E=Q^2/(8πϵR) Self Energy The Attempt at a Solution In this problem, electric...
  40. Saitama

    Electrostatic potential energy - dielectric between concentric spheres

    Homework Statement A conducting sphere of radius ##a## carries an initial charge ##q_o##. It is surrounded by another concentric sphere of radius ##b##. The space between the two spheres is filled with a dielectric of permittivity ##\epsilon## and conductivity ##\sigma##. Find the electrostatic...
  41. P

    Electrostatic Potential Problems

    Homework Statement I'm currently tackling parts (a) and (b) of section ii) decribed here:http://puu.sh/31KIZ.png Homework Equations V=(q/4∏ε)*(1/r) The Attempt at a Solution From the first section (i) calculating the potential was relatively straight forward since we were only...
  42. U

    Electrostatic collision between two masses

    Homework Statement Homework Equations The Attempt at a Solution I've done part (a) and (b) using conservation of momentum and energy..for part (c) I'm not sure how to find the minimum angle ∅. I have also worked out the velocities of m1 and m2 just before the collision as...
  43. S

    Does the Electrostatic Force Originate from Curvature? An Explanation

    einstein explained the origin of gravitational force from the concept of space time curvature.but what about the electrostatic force...does it also originate from some sort of curvature.please explain...
  44. Z

    Past exam question about electrostatic field and potential

    Homework Statement Using Stoke’s theorem and the identities given, ∇x∇(Scalar)=0 deduce the relationship between electrostatic field E and potential ψ at a point in space, show that E = -∇ψ Homework Equations The Attempt at a Solution Does this question mean show a derivation...
  45. X

    Work done by electrostatic force

    Homework Statement A small, positively charged sphere is released from rest and moves directly away from a larger, positively charged sphere. During this process, the electrostatic force: a) does positive work and increases the kinetic energy of the small sphere b) does negative work and...
  46. D

    Effect on electrostatic force due to dielectric medium.

    Hi! I have a high school physics question. I know the concept of induction, and I also know what happens when a dielectric slab is placed between 2 plates of a capacitor. 2 charged particles are kept at a distance r. The mutual force of attraction/repulsion is F. What happens to the force...
  47. D

    Can a Highly Charged Rod Strip All Electrons from Aluminum Foil?

    Homework Statement If there is a positively charged rod,which is placed near an aluminium foil,free electrons in the foil are pulled towards the rod.This makes the top end of the foil negative and leaves the bottom end short of electrons to become positive. I wonder if the rod has a very...
  48. M

    Electrostatic force and Gravitational force

    I have physics homework and came across this question : I was asked to find the electrostatic force between two charged particles each having a charge of +5.0x10-9 C and which were separated by a distance of 3cm. I found it to be 2.5x10-4 N.Then I was told to calculate the gravitational force...
  49. Roodles01

    Determine whether vector field is magnetic or electrostatic

    Homework Statement Three vector fields are listed below. Determine whether each of them is electrostatic field or magnetic field.Homework Equations F1(x, y, z) = A (9yz ex + xz ey + xy ez) F2(r,∅,z) = A [(cosx/r)er + (sinx/r) e∅] F3(r,θ,∅) = Ar2 e(-r/a) erThe Attempt at a Solution Used matrix...
  50. N

    How Do Electrostatic Speakers Use Voltage to Create Pressure?

    Homework Statement An electrostatic speaker is constructed using two conductive plates (stators) and an electrostatically charged diaphragm in the middle which vibrates. One of the conductors is grounded, and the other has an amplified voltage applied to it to drive the force. A uniform...
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