What is Charge: Definition and 1000 Discussions

Homework Statement Homework Equations / 3. The Attempt at a Solution [/B] Here is what I attempted for the HW. I only got 2/10 for this here so I'm wanting to correct my mistakes.

1. Find the magnitude and direction of the force experienced by the charge of 3microcoulombs.Homework Equations After subtending forces of both the particles on the third one, we need to find the aggregate magnitude of the charge experienced by it. The Attempt at a Solution I was able to find...

Homework Statement From the textbook: Homework Equations / 3. The Attempt at a Solution My attempt at the solution: looking to fix my issues and help correcting my work.[/B]

In Berkeley Physics Course (Volume II) on Electricity and Magnetism: https://www.scribd.com/doc/128728926/Electricity-and-Magnetism-Berkeley-Physics-Course-Purcell ...Purcell discusses the invariance of charge (Section 5.4), the electric field measured in different frames of reference (Section...

There are two charges with charge q and mass m and they are in equilibrium. Then, in the diagram why is my teacher saying that electrostatic force(F)=mg? Below is diagram.

Homework Statement : STATEMENT:[/B]A point charge at rest is released in an electric field. It will move along the electric field line...(1) REASON: The force on a point charge is along the field line...(2) State whether: A) 2 is the correct reason for(1) B) Both (1) and (2) are correct but 2 is...

I'm working on a finite element simulation of the electrostatic potential V(r) in and around semiconductor nanowires, based on solving Poisson's equation. While the details of the problem will follow shortly, the crux of where I run into trouble is that for nanowires it is important to include...

Homework Statement Four particles with equal charges q and equal masses m are placed on a plane so that they form the corners of a square with side length a. The charges are then released from rest at this configuration (shown as (i) in the figure). After the release, the particles accelerate...

Homework Statement Homework EquationsThe Attempt at a Solution I don't understand what is the meaning of "potential of cylinder relative to the plane" I think the potential of cylinder is just -q/2πε ln r by Gauss's theorem[/B]

Which property of compounds, organic ones in particular, can help us predict their charge(s) at a specific pH? Is pKa/pKb the only one? I would like some confirmation on this. Thank you very much!

Homework Statement In an abrupt p-n junction we consider the junction between one side p-doped with ##N_A## acceptor atoms and another side n-doped with ##N_D## donor atoms. Initially the chemical potential is different in the two sides, but thermal equilibrium requires that the chemical...

A few dozen years ago the endings of lightning rods were sharp. I read somewhere that it served one purpose - it enabled the flow of charge between the ground and the cloud, thus reducing the voltage and lessening the probability of another lightning. What I don't understand is why this sharp...

I need help trying to set up this problem. I want to find the capacitance between a point charge and a finite plate (or disk) as the point moves from above the center of the plate to some distance off the plate. I have been able to simulate this problem using FEM, however, there should be a...

Years ago I read an article illustrating the vastly different strengths of the electromagnetic and gravitational forces. The article gave a figure for the number of excess electrons dispersed throughout the Earth that it would require to overcome the gravitational binding of Earth's matter and...

Homework Statement Use Gauss's law to find the electric field caused by a thin, flat, infinite sheet with a uniform positive surface charge density σ. Homework Equations φ(flux) = ∫E*dA = qencl / ε0 The Attempt at a Solution I set up a diagram like this...

Homework Statement A metallic sphere of radius a is placed concentrically with a metallic spherical shell with inner radius b and outer radius c. The sphere has a total charge of 2Q and the shell has a total charge of 3Q. (a) What is the charge distribution? Specifically, what is...

Homework Statement Theres a cylinder rod inner radius a outer raidus b.we want to find electric field between a and b,like point r (or radius r) a<r<b. Homework Equations Gauss Law The Attempt at a Solution [/B]I am trying to find Q enclosed but something make me confused.I am...

I need a flux of highly positive ions, at least penta-valent ions (5+ or more, 6+, 7+, ...); there are ion sources that can generate a proton flux, but I need 5+ ions; do you know how I can do that?

Homework Statement http://imgur.com/a/TOUjV part b, specifically finding the maximum charge for C1. The question that boggles me is whether Imax changes on the left side of the circuit, after the switch closes. Homework Equations V=IR Xc = 1/(wC) XL = wL The Attempt at a Solution I was able...

Hello, I am trying to solve an issue which occurs when two robots with different static charges make contact. It has been some time since my Physics classes and I have some ideas that are only partly making sense to me. I need to minimize the effect that a static shock is having on a small...

Homework Statement a) Common transparent tape becomes charged when pulled from a dispenser. If one piece is placed above another, the repulsive force can be great enough to support the top piece’s weight. Assuming equal point charges (only an approximation), calculate the magnitude of the...

I'm working on this: When I consider a disc with radius ##a## and total charge ##Q## uniformly distributed (placed in the XY plane and centered at the origin) and determine the volume charge density in cylindrical coordinates, I have assumed is of the form ##\rho=A \delta (z) U(R-r)##, (##U## is...

Homework Statement 2 large plates are separated by a distance d and a space charge of uniform charge density p is placed between them and a potential difference V is applied across the plates. Find the electric field stength at a distance x fromt the positive plate The answer is -V/d...

Homework Statement Below are a few equations listed in my text for use in calculating capacitance in dielectrics. I'm wondering which of these are applicable in specific scenarios Homework Equations 1. k = C/C0 - with C0 indicating capacitance w/o dielectric 2. v = v0/k 3. E = E0/k 4. σi = σ(1...

Question: If you charge a capacitor circuit and then separate the capacitor, does voltage increase beyond the initial source? It seams counter intuitive that if you plug a 9 Volt battery into two metal plates and pull the plates apart that you'll get massive voltage spikes, but that's what the...

Homework Statement A small sphere with mass 5.00×10−7 kg and charge +6.00 μC is released from rest a distance of 0.400 m above a large horizontal insulating sheet of charge that has uniform surface charge density σ = +8.00 pC/m2.Using energy methods, calculate the speed of the sphere when it is...

Homework Statement My questions are just related to part a of this problem. Homework EquationsThe Attempt at a Solution I know that potential inside a conductor is equivalent to potential on the surface of the conductor and potential at any point is an algebraic sum of potential...

I have a question about definition of charge neutral point. I`m reading some article about trilayer graphene, and this term, charge neutral point, is used in the article. I googling this word, but I can`t find something which can tell me what it is. In monolayer graphene, what i found by...

I have been using Maple for sometime as its document interface feels nicer and more friendly than mathematica's . I have never been able to plot arrows in Mathematica or use indices efficiently. I am more of a curious self teaching physics person. But I just found something interesting when...

Homework Statement We have an electric dipole with moment P=2*[10][/-5] pointing in x direction. What is the force experieced by dipole at origin when a point charge Q=3*[10][/-4] is located at (0.014 m ,0,0) Homework Equations 1. [E][/dipole]=(1/4π[ε][/0])(2p/r3) 2. p=qs 3. F=qE 4. τ=pEsinϑ...

Homework Statement Homework EquationsThe Attempt at a Solution I have the full solution, the first part being: I don't understand how they came up with the expression for Vab. I know usually ΔV=-∫E dl, but I'm not sure how they found their expression. Can someone explain? Thanks.

Homework Statement One type of ink-jet printer, called an electrostatic ink-jet printer, forms the letters by using deflecting electrodes to steer charged ink drops up and down vertically as the ink jet sweeps horizontally across the page. The ink jet forms 29.0 μm diameter drops of ink...

Homework Statement At a distance D from a very long (essentially infinite) uniform line of charge, the electric field strength is 1000 N/C. At what distance from the line will the field strength to be 4000 N/C? Homework Equations E=kq/r2 The Attempt at a Solution I know that E is inversely...

Hi. Inductance and capacitance have many analogies, both conceptually and formally. A capacitor connected to a voltage source carries the charge ##Q=C\cdot V##. The analogous equation for inductance is ##n\cdot \Phi=L\cdot I##. Charge is physical, it's proportional to the number of excess...

Homework Statement Insulator has a 3 cm radius and is a sphere. It has a total charge of -4.2 uC. I need to find the charge density of the insulator. Homework Equations sigma = total charge / volume... I think? The Attempt at a Solution After using the above equation, I got -3.714E-8 C/m I...

Homework Statement Calculate the surface charge density induced by a point source above an infinite conducting plane, with 0 potential. Homework Equations ##E=-\nabla V## ##V=\frac{q}{4\pi \epsilon_0 r}## The Attempt at a Solution I used the method of image charges and I calculated the...

Homework Statement Charge q1= 8.5 nC is located at the coordinate system origin (0,0), while charge q2= -4.46 nC is located at (a,0), where a= 1.5 m. The point P has coordinates (a,b), where b=0.95 m. A third charge q3= 16.5 nC will b added later. It is a 3 part question, first asking for the...

Homework Statement Given the electric potential ##V(r)=A\frac{e^{-\lambda r}}{r}## calculate the charge density ##\rho(r)## and the electric field ##E(r)##. They specify the answer for charge density should be: ##\rho = \epsilon_0 A(4\pi \delta^3(r)-\lambda^2e^{-\lambda r}/r)## Homework...

Hello! I am a bit confused about calculating the induced surface charge density on an infinite conducting plane, with 0 potential, in the presence of a charge, q, a distance d above it. Assuming that the plane is in xy plane and the charge in positive z region, in the book they use the method of...

The momentum-space fermion propagator in the free Dirac theory is given by The arrow on the fermion propagator is said to represent the flow of charge. How can we derive this statement quantitatively from the Dirac Lagrangian? What is the quantitative form of the charge being referred to here?

Homework Statement In the figure, a proton, mass 1.67×10^−27 kg, is projected horizontally midway between two parallel plates that are separated by 0.20cm, with an electrical field with magnitude 7.8×10^5N/C between the plates. If the plates are 5.40cm long, find the minimum speed of the proton...

Homework Statement An electric circuit is shown as above. The switch S is closed for a long time and the current flowing is constant. Given that C1 = 3 μF, C2 = 6 μF, R1 = 4 kΩ, R2 = 7 kΩ If the power at R2 resistor is 2,4 W a) Determine the charge at C1 b) When the switch is opened, after...

Homework Statement Here are the problem statement and the solution. I'm stuck at where the book suggests the formulas for the x and y coordinations (highlighted in yellow) of the third charge. Any explanations or proof on how they came to the conclusion for the third charge coordinations would...

Homework Statement Homework Equations Gauss The Attempt at a Solution I am really confused with question a, I have an idea of how to answer b and c once I obtain an answer for part a... My best guess would be to use Gauss, but I am not sure. Would the field inside be 0? What will the bounds...

Homework Statement The potential difference between the surface of a 2.2 cm -diameter power line and a point 1.9 m distant is 3.8 kV. What is the magnitude of the line charge density on the power line? Express your answer using two significant figures. Homework Equations V =...

Homework Statement The electric field strength just above one face of a copper penny is 2230 N/C. What is the surface charge density on this face of the penny? Homework Equations Electric field of an infinite plane of charge = η/(2*ε0) The Attempt at a Solution I used the above equation, and...

Hi all, this question comes from an old related thread .. https://www.physicsforums.com/threads/help-in-semiconductors-minority-and-majority-carriers.613598/ I'm also interested in the definition of these 'minority charge carriers' in semiconductors. I don't understand the explanations in the...

Chapter 24, Question 61 Given two configurations, ##C_1##, ##C_2## of ##N## point charges each, determine the smallest value of ##N## s.t. ##V_1>V_2##. ##C_1##: ##N## point charges are uniformly distributed on a ring s.t. the distance between adjacent electrons is constant ##C_2##: ##N-1##...

Homework Statement Two 10-cm-diameter metal disks separated by a 0.64-mm-thick piece of Pyrex glass are charged to a potential difference of 1100 V . What is the surface charge density on the disks? What is the surface charge density on the glass? Homework Equations C=(e_0A)/d C=Q/V charge...

Homework Statement A uniformly charged thin ring has radius 13.0 cm and total charge 21.5 nC . An electron is placed on the ring's axis a distance 32.5 cm from the center of the ring and is constrained to stay on the axis of the ring. The electron is then released from rest. Find the speed of...