Charge Definition and 1000 Threads

  1. nashikin58

    How to avoid a clash of magnetic charge and electric charge

    Hi, now I'm working on a project which involves a dc motor and high voltage. I'm developing a machine consists of a motor to rotate a platform disc and high voltage will be applied during the rotation. The problem is when I supply a positive high voltage at motor shaft during rotation, the motor...
  2. K

    Charge-Dipole Derivation - Assumption That x >> a

    In this derivation: https://cpb-us-e1.wpmucdn.com/sites.northwestern.edu/dist/8/1599/files/2017/06/taylor_series-14rhgdo.pdf they assume in equation (8) that x >> a in order to use the Taylor Expansion because a/x has difficult behavior. Why does that assumption work? Meaning, why can we...
  3. HCverma

    Where does the negative charge come from in H2S?

    If we split H2S we get H2S = 2H+ + S2- Where does the negative charge come from in H2S? Do we get 2- charge from the 2H atoms (now two protons after losing the electrons), I mean 2H+ or 2 protons get separated leaving behind the two electrons on S?
  4. HCverma

    In coordinate bond, why doesn't the H^+ atom get a negative charge?

    In a coordinate bond, why H^+ atom don't get the negative charge? as an example [NH4]^+ If we split [NH4]^+, we get NH3 + H^+. In NH3, N and 3H atoms have completed their octet and H^+ accepts the lone pair of electrons from the N, As we know H^+ has no any electrons but a proton. If it receives...
  5. H

    Conductors in capacitor equal but opposite charge?

    Homework Statement If you put a capacitor in some circuit, why exactly do the conductors that form the capacitor have equal and opposite charge? This seems to be assumed in many cases. Homework Equations Is it possible for the conductors to have different magnitude of charge?
  6. A

    Measuring Charge on a Van De Graaff Generator: Methods and Obstacles

    Greetings, Does anyone know of a way to measure the actual charge of a Van De Graaff generator, in Coloumbs? One way I thought might be to measure the voltage potential around the generator, and calculate the charge from V = kQ/r, but would this work in just regular air? What obstacles would...
  7. V

    Capacitor problem with a beam balance -- balancing after changing the charge

    The lower plate of a parallel plate capacitor is supported on a rigid rod.The upper plate is suspended from one end of a balance.The two plates are joined together by a thin wire and subsequently disconnected.The balance is then counterpoised.Now a voltage V= 5000V is applied between the...
  8. HCverma

    Chemistry How to calculate the maximum charge of an atom or a molecule

    Homework Statement How to calculate the maximum charge of an atom or a molecule? As we know the equivalent weight = atomic weight / maximum charge Al, Ca and O2The Attempt at a Solution Al, E = 27/3 = 9 Ca, E = 40/2 = 20 O2, E = 16/2 = 8 I see on the books that the charges of Al, Ca and O2 are...
  9. F

    Flow of charge between two spheres

    Lets say I have two spheres of equal dimensions, one charged and one uncharged. Now I connect them with a conducting wire. They will now very quickly reach equal potential. Can it be said that the total charge on each sphere remains almost unchanged?
  10. B

    Effective Charge on Valence Electrons of Sb

    Homework Statement Given Slater's expression for effective charge below, determine the effective charge experienced by the valence electrons of Sb.Homework Equations Zeff = Z - 0.35a - 0.85b - c Where Z= the nuclear charge; a= the number of s and p electrons in the same shell; b= the number of...
  11. K

    B LC Oscillation: Current Flow & Charge Polarity

    when in LC oscillation current flow from inductance to capacitor and charge is opposite polarity. why don't current flow in reverse of it and charging the capacitor in same manner as it was earlier.
  12. F

    Charge on Sphere: Evenly Spreading?

    Lets say I have a conducting neutral sphere containing a spherical hollow space. The hollow space contains a point charge at its center. This setup will result in a charge equal in magnitude with opposite sign of the point charge spreading evenly over the boundary of the hollow space and a...
  13. F

    How does grounding cause dissipation of charge

    When an object with a net charge is connected to the ground by some conducting material the net charge disappears. The only answer I was able to find was that the net charge gets spread out, which will clearly cause it to become negligible. What causes this to happen?
  14. S

    Is the following decay process possible?

    Homework Statement An antimuon and electron may bind together via Coulomb attraction and then decay, but is the following process possible? (µ+e-) → νe + νµ_bar *The νµ_bar is the antiparticle of the muon neutrino - the antimuon neutrino More than one answer (below) may be correct. a)...
  15. A

    Capacitors: find he charge for the new battery

    Homework Statement A capacitor stores 7.9 x 10-2 C of charge when connected to a 6.0-V battery. How much charge does the capacitor store when connected to a 9.0-V battery? Homework Equations PE=CQ/2 The Attempt at a Solution QV^2=CQ^2 (7.9 x 10-2)(6)/2 = Q(9) C= .05 C
  16. QuasarBoy543298

    I Force on Moving Charge: Lorentz Transformation & Point Charge

    consider a frame S with a given electric and magnetic fields , and a single point charge. if we want to calculate the force on the charge in his rest frame we should use Lorentz transformation to find the electric field in his rest frame. if we believe that a given field is not related to his...
  17. Sandeep T S

    Charge and Velocity: Does Moving Particle Charge Increase?

    Is charge of moving particle increase? Is any experiment done on this,?
  18. BillTre

    Spiders Flying by Electrical Charge

    Some spiders are known to fly on the breezes by extruding silk strands (like web material) from their abdomen. This is commonly thought to be caught in the wind and carry them away. This would explain the occasional spider you might see drifting by when you are outside. Many (including that...
  19. S

    B Understanding Energy and Charge: Exploring the Basics

    I have a simple two-part question, or two simple questions. 1. What is energy? 2. What is charge? The charge I'm referring to is the charge on charged subatomic particles. And atom's charge is defined by the number of electrons and protons present in it. But an electron itself is called a...
  20. A

    Poynting vector - uniform vs accelerated charge

    I am trying to understand why an accelerating charge emits radiation/electromagnetic waves but a uniformly moving one does not. I saw one video on Youtube where it seemed that it was explained by the fact that with a uniformly moving charge the Poynting vector was pointing 'in to the volume' -...
  21. A

    Coulomb's Law and charge quantization

    Coulomb's law states that the force between particles depends on their charge. But protons and electrons have equal but opposite charges. Shouldn't the formula simply have constants with the only changes required being the signs?
  22. Zahid Iftikhar

    Uniform Field due to an Infinite Sheet of Charge

    Hi I have read one excellent explanation on the question I am posting again, at another thread on PF, because I am not able to completely understand the concept. Please spare some more time. I need help to understand how an electric field due to an infinite sheet of charge can be uniform where...
  23. E

    A generic quantum state and the charge of an electron

    I'm watching a lecture and the professor is talking about generic quantum states as |\psi> He's making the point that this state is very generic. It can represent anything. He references some examples like the polarization of a photon and the path of a photon and the spin of an electron...
  24. A

    Charge on a rod of infinite length

    1. Charge is distributed through an infinitely long cylinder of radius R in such a way that the charge density is proportional to the distance from the central axis: ß = A r, where A is a constant and ß is the density. (a) Calculate the total charge contained in a segment of the cylinder of...
  25. Z

    Electric Field Outside of a Ring of Charge in the X-Y Plane

    If I try to calculate the electric field in the x-y plane of a ring of charge resting at the origin on the x-y plane, I keep getting zero. I start with Coulomb's Law. $$ dE(r) = \frac{1}{4\pi\epsilon}\frac{dq}{r^2} = \frac{\lambda R}{4\pi\epsilon}\frac{d\theta}{r^2},$$ in which ##\vec R## is...
  26. D

    Voltage vs Charge: Capacity & Applied Voltage

    If voltage is the difference in charge between 2 points, then why for a capacitor of a larger area or thinner dielectric cross section, do they say that it can store more charge given the same apppied voltage? Isnt voltage the difference in charge between 2 points? So if you can store more...
  27. CDL

    Electric Flux through the Face of a Cube

    Homework Statement Griffiths' Introduction to Electrodynamics problem 2.10, Homework Equations Gauss' Law, ##\int_{S} \textbf{E}\cdot \textbf{dS} = \frac{Q_{\text{enc}}}{\epsilon_0}##[/B]The Attempt at a Solution It seems reasonable that the flux through the shaded surface and the front...
  28. CDL

    Point Charges on a Polygon with another Charge in the Middle

    Homework Statement Suppose we have a regular n-gon with identical charges at each vertex. What force would a charge ##Q## at the centre feel? What would the force on the charge ##Q## be if one of the charges at the vertices were removed? [/B]Homework Equations Principle of Superposition, the...
  29. MichPod

    Does "magnetic charge" fit into vector potential?

    Disclaimer: I am not a physicist, just trying to learn some parts of it in my free time. And I do not mean to propose any kind of "new-theory" with my question. I always thought that Maxwell equations in their differential form for B and E may be reformulated/updated to include a magnetic...
  30. R

    Calculating Work to Charge Parallel Conducting Plates

    Homework Statement A pair of parallel conducting plates, each measuring 30 cm X 30 cm, are separated by a gap of 1.0 mm. How much work must you do against the electric forces to charge these plates with ##+1.0 \cdot 10^{-6} C ## and ##-1.0 \cdot 10^{-6} C##, respectively? Physics for Engineers...
  31. Manav

    Calculating Charge Of Electron (Millikan Oil Drop Experiment

    Homework Statement I was doing the Milikan Oil Drop Experiment from a simulation this site: http://scienceclub.ucoz.com/index/0-109. I tried calculating the charge of the electron but it was from the real value. Oil Density: 920 (kg/m^3) Viscosity of Air: 1.81×10−5 kg/(m*s) Distance: 0.0025 m...
  32. F

    Charge on the capacitor after changing the switch position

    Homework Statement Homework Equations V = I R Q= CV The Attempt at a Solution When the switch is connected to position a : 20-106 * I = 0 ( KVL) Vc = 0 , because the switch is connected for a long time. I = 2*10-5 A When the switch is connected to position b : Q/(4*10-6) - 106 *2*10-5 = 0...
  33. J

    How Much Charge Does a Defibrillator Capacitor Store After 1.10 Seconds?

    Homework Statement Defibrillation[/B] is a common treatment for life-threatening cardiac arrhythmias and ventricular fibrillation. The defibrillator applies a current across the heart (shown by the red arrows in the image below) for a short time (a few milliseconds), disrupting the arrhythmia...
  34. H

    Electric Force on a Charge in a Solenoid

    Homework Statement [IMG]http://[url=https://ibb.co/dgUy6T]https://preview.ibb.co/iyqS0o/20180525_213806.jpg Since i only know the field direction, increasing go into page. Why the answer is C? Why the answer "a" ? The R and r on the pic is respected to what? Homework EquationsThe Attempt...
  35. C

    Work done per unit charge by electric field on charge

    Homework Statement Homework EquationsThe Attempt at a Solution I know the units for V is J/C so #3 and #4 are wrong. But how do I determine the signs?
  36. S

    What is the electric charge on the charged polystyrene ball?

    Homework Statement A charged polystyrene ball of mass 0.14g is suspended by a nylon thread from a fine glass spring. In the absence of any electric field the spring extends by 30mm. The polystyrene ball is then placed in an electric field that acts vertically upwards, of strength 200kV m^-1...
  37. Nod

    A Charge density of carbon nanotubes and graphene

    Hi everyone! I'm trying to solve the following problem: given the charge densities of carbon nanotubes and graphene, the charge density difference of 2 systems must be found. So I need to unfold in some way the nanotube and compare it charge density with the graphene's one. But how this...
  38. prodo123

    (General question)Area charge density and electric potential

    Homework Statement Sorry, the post isn't about a single homework problem but rather something that I keep getting confused on. It's about calculating the electric potential of a spherical shell of uniform charge in two different ways. Homework Equations ##\Delta V=\int_a^b -\vec E\cdot d\vec...
  39. prodo123

    Electric potential inside a shell of charge

    Homework Statement Q1: There are two concentric spherical shells with radii ##R_1## and ##R_2## and charges ##q_1## and ##q_2## uniformly distributed across their surfaces. What is the electric potential at the center of the shells? Q2: There is an infinitely long hollow cylinder of linear...
  40. Islam Hassan

    I Electron/Proton Electric Charge Equality Expected?

    Do the SM and Lambda-CDM lepton-era models predict that the electron’s isolated electric charge be equal in magnitude (to 12 significant figures) to that of the proton which is a composite particle? What makes that this identity in electric charge magnitude is so exquisitely ‘fine-tuned’? What...
  41. g98

    Find charge inner/hollow sphere

    Homework Statement A hollow conducting sphere with an inner radius of 5 cm and an outer radius of 6 cm contains a smaller sphere of radius 3 cm, located symmetrically inside the hollow sphere. The electric field strength at 4 cm from the center is measured to be 2400 N/C pointing inward. The...
  42. J

    What is the net charge on a magnesium ion after losing two electrons?

    Homework Statement Calculate the net charge on a magnesium ion which has lost two electrons. 2. The attempt at a solution I put 2+ as my answer and this is what I was told, but I don't understand what they mean by the following; That's a chemist's shorthand, not the amount of charge on the...
  43. Zubair Ahmad

    If charge is decreasing with time then we write I =-dq/dt.

    What does the negative sign tell?
  44. J

    What is the minimum charge needed for a ball to jump in an electric field?

    I don't really know how to fit what i want to this template, but i'll try. The thing is that i wonder if anyone can explain to me step-by-step what happened in this solution, because i don't really understand it. Homework Statement There are two balls. Upper one(mass m, charge Q) hung on a...
  45. F

    Find the charge on the capacitor and the currents

    Homework Statement Homework Equations ##Q=CΔV## ##V=IR## The Attempt at a Solution Is my answer correct ?
  46. sweet springs

    Gravity and radiation from charge

    Reading a thread in relativity I would like to know more precisely about radiation from charge. 1 I put a charge on the table of my house. Gravity and table reaction force work on the charge. They cancel so net force does not work on the charge, thus no-force no-velocity cause no radiation...
  47. F

    Find the charge on the positive circular plate

    Homework Statement Homework Equations Q = C ΔV C = ##\frac{ε A}{d}## The Attempt at a Solution A = π R2 Q = (π R2*ε V)/d Is my answer correct ?
  48. L

    Express E due to a point charge at the origin

    Homework Statement Express the electric field E due to a point charge q at the origin in cylindrical polar coordinates. Homework EquationsThe Attempt at a Solution Know that E = q / 4*pi*epsilon_0*r^2 in the r-direction, which is the answer in spherical coordinates. How we we swap to cylindrical?
  49. Sandeep T S

    Is like currents of opposite charge attract or repel each other?

    Is like currents of opposite charge attract or repel each other
  50. M

    Radiation field of charge moving in a circular loop

    Homework Statement [/B] I need to calculate de radiation field produced by a charge moving in a circular loop of radius a, considering the motion is not relativistic and zone of radiation (far field) .Homework Equations The scalar potential is: $$ V=\int \dfrac{\rho(x')}{|x-x'|}d^3x'$$ The...
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