Charge density Definition and 419 Threads

I still don't understand from the msg given... another explanation any1 Hey I have two questions... the first one I did I got wrong but am really unsure why... I used sigma=Q/A but didnt get the right answer... I got that the answer was 1.3277E7 but I am so far off it aint funny! Please...

OK, I may be out of my league here so feel free to let me know (in a nice way please) but conceptually & every other way I can come up with, I am trying to put together volume charge density, linear charge density and surface charge density ... for example in my text it says that in terms of a...

[FONT="Arial"]I am never sure if I am on the right track when answering my homework problems. Anyway the problem involves a long solid cylinder of radius R and uniform charge distribution throughout its volume. We are supposed to choose a cylindrical gaussian surface of radius r and length L...

I've been struggling over this the entire weekend and am about to rip my hair out. Suppose we have some object with a mass M and a charge Q. It floats above the center of a large horizontal plastic sheet with a uniform charge density on its surface. What is the charge-per-area (sigma) on...

Consider a solid insulating sphere of radius b with nonuniform charge density \sigma = ar where a is a constant. Find the charge Q_r contained within the radius r, when r < b. Note: The volume element dV for a spherical shell of radius r and thickness dr is equal to 4\pi r^2 . I got this...

In a particular region of the Earth's atmosphere, the electric field above the Earth's surface has been measured to be 155 N/C downward at an altitude of 271 m and 175.5 N/C downward at an altitude of 409 m. The permittivity of free space is 8.85 x 10^-12 C^2/Nm^2. Neglecting the curvature of...

What is the electric field inside a sphere of radius R when the charge density is given by: \rho=\frac{A}{r} Where A is a constant, and r is the radius at where the charge density is to be evaluated. By Gauss' law I have calculated the field to be equal to: E=\frac{A}{2\epsilon_0} But that...

An electron remains stationary in na electric field directed downward in teh Earth's gravitational field. If the electric field is due to charge on the two large conducting plates oppositely charged and separated by 2.3cm what is the surface charge density assumed to be uniform on the plates...

(src: Intro to Electrodynamics, Griffith, Problem 1.46a) Q: Write an expression for the electric charge density \rho (r) of a point charge q at r^'. Make sure that the volume integral of \rho equals q. Now, Closest I can seem to come up with is...

A little while ago I posted a thread asking the same question but didn't really get an answer so I am going to try to rewrite it. I'm having trouble understanding how the charge density of an electron (or any particle) is the square of its wave function. One problem I have is when there are...

Helllo everyone I'm stuck. A sphereical metal satelliete 1.3m in diameter accumulates 2.4x10^-6 C of charge in one orbital revolution. Find the resulting surface charge density. This is a simple plug in chug problem i think...I know the charge and radius but i can't finda formula that works...

Hello everyone... I'm suppose to determine the charge density on either plate. I attached a file which shows the diagram of what I'm talking about. I understand there is no field inside the conducting plate, and the only area penetrated by the field lines is the surface A' projtecting into...

Three very large square planes of charge are arranged as shown (on edge) in Fig. 21-70. From left to right, the planes have charge densities per unit area of -0.50 µC/m2, +0.20 µC/m2, and -0.30 µC/m2. Find the total electric field (direction and magnitude) at the points A, B, C, and D. Assume...

silly question i guess, but is charge density defined only for stationary charges? i'm asking this because I did a couple homework problems on finding electric field in linear dielectric material. Dielectric is between two surfaces held at constant potential difference (ie. parallel plate...

28. The problem is stated as: A long, thin wire carrying 5.6nC/m runs down the center of a long, thin-walled, hollow pipe with radius 1.0cm carrying -4.2nC/m spread uniformly over its surface. (a)Find the electric field 0.50 cm from the wire. (b)Find the electric field 1.5 cm from the wire...

At two different points of an irregularly shaped conductor, the field had the following two values 5.6*10^4 and 2.8*10^4 respectively. Find the local surface charge density at; 1- the point with the greatest radius of curvature, 2- the point with the smallest raduis of curvature. I know...

I've done a search for some help on my problem, but I haven't seen anything resemble it. Anyway my question is the following: Not all dielectrics that separate the plates of a capacitor are rigid. For example, the membrane of a nerve axon is a bilipid layer that has a finite compressibility...

One problem I can't solve. A uniform charge density of p coul/m3 is in the shape of a sphere of radius R. Find expressions for the potential V and the field E at a distance r from the center, for points inside or outside the sphere. Can u help me?

Hi all, I cann't figure out the relationship between a current and the charge density. I have a current Io which circulated in a hollow cylindrique, how can I related with the charge density? Something like charge density = Io * ... Thanks in advance, Mica