Gauss's law — 382 discussions

I have a question about electric flux. Intuitively it makes that if a charge is outside a closed object, then the net flux inside that object will be zero..but once I write it down on paper it loses its sense. I attached a picture for clarification. Flux is equal to the field, times...

I was wondering, how would you prove Gauss's law (either mathematically or intuitively)? I mean, I know that sometimes people take it as the fundamental law (one without proof) but how would you derive such a law from Coulomb's law? Any help would be extremely appreciated. I have been fussing...

Hello, everyone. I have a problem that I solved using Gauss's Law. However, I am unconfident in my answers, as I have very little experience with Gauss's Law. The surfaces of two large (i.e. infinite) parallel conducting plates have charge densities as follows: \sigma_1 on the top of the top...

Ok guys, these are just questions from our book(like critical thinking type)...she said to be able to understand these, for the upcoming test. I'm not sure I fully understand them(if at all). 1. If a closed surface surrounds a dipole, the net flux through the surface is zero. True or...

I understand how to use Gauss's law to calculate the electric field at some point for say a sphere with charge distributed uniformly in it. I am bit confused, though, about calculating the electric field at some point for a non-uniform charge distribution. For example, say that I have a...

Hey guys, before I post I want to say that I am still learning this concept and just want clarification. Why do the charges inside a metal or other object that are interacting(repelling for instance) eventually come to rest and not continue to keep moving around constantly repelling one...

First could someone actually explain the following question to me! Consider a hydrogen atom to be a positive point charge e at the center of a uniformly charged sphere of radius R and with total charge -e. Using Gauss' Law, find an expression for the electric field as a function of the...

I need to show that \vec{\nabla} \cdot \vec{E}= \frac{\rho}{\epsilon_0} where \rho is the volume charge density. I know that if I can show that the net flux of the electric field (in three directions xyz) out of the a small gaussian surface in the shape of a cube with faces parallel to...

A region in space contains a total positive charge Q that is distributed spherically such that the volume charge density rho (r) is given by: rho (r)=3 * alpha * r /(2R) for r ≤ R / 2 rho (r)= alpha * [1-(r/R)^(2) ] for (R/2) ≤ r ≤ R rho (r)=0 for r ≥ R Here alpha is a positive...

Okay, first off, some quick background. I am a student in AP Physics C, and I like to think I generally have a good grasp of physics (I read about it outside the class). We just learned about Gauss's Law this week, and I have a good grasp of it. I understand how it can be used to simplify some...

A conducting sphere of radius 10 \mbox{ cm} has an unknown charge. If the electric field 17 \mbox{ cm} from the center of the sphere has the magnitude 3.2 \times 10 ^3 \mbox{N/C} and is directed radially inward, what is the net charge on the sphere? Let: R = 10 \mbox{ cm} r = 17 \mbox{...

Hey everyone, I have two problems that deal with Gauss's law. The first one deals with Electric Fields. Charge is distributed on a long, straight rod with uniform density 6.5 x 10^-8 C/m. Compare the magnitude of the field 1 cm from the rod to the field 1 cm from a point charge q = 6.5 x...

I have two plates, one on top of the other, that have a charge densities +s1 of the top of the top plate, -s2 on the bottom of the top plate, s2 on the top of the bottom plate, and -s1 on the bottom of the bottom plate (s1 and s2 are both positive numbers). I have to find the electric field on...

I'm a senior in high school, and I have a physics research paper due on Thursday. The problem is, I don't know what Gauss's Law is. So I googled it. In physics, Gauss's law gives the relation between the electric flux flowing out a closed surface and the charge enclosed in the surface. I...

A thin cylindrical shell of radius R1 = 5.0 cm is surrounded by a second cylindrical shell of radius R2 = 9.0 cm, as in Fig. 22-34. Both cylinders are 3.0 m long. The inner one carries a total charge of Q1 = -3.8 µC. The outer one carries a total charge of Q2 = +2.2 µC. (Assume the positive...

A flat square sheet of thin aluminum foil, 25 cm on a side, carries a uniformly distributed -36 nC charge. What is the approximate electric field at the following positions? a.)0.01m above surface? b.) 20m above the sheet? For a.), I used E=chargedensity/(2)epsilon. From my...

"A solid conducting sphere with radius R carries a posative total charge Q. The sphere is surrounded by an insulating shell with inner radius R and outer radius 2R. The insulating shell has a uniform charge density \rho a) find the value of \rho so that the net charge of the entire system is...

I am stuck on this one. I apprciate your help greatly. A cyllindrical shape of radius 7cm and length 240 cm has its charge uniformly distributed on its curved surface.The magnitude of the electric field at a point 19cm radially outward from its axis (measure from the mid point of the shell)...

An infinitely long line charge having a uniform charge per unit length (half-life - if anyone could tell me the correct name for that symbol it would be great too :)) lies a distance d from the point O, where the point O is the center of a sphere. Determine the total electric flux through the...

Hi all, Can someone give me a better explanation of precisely what Gauss's law and the term "electric flux" mean (better, that is, than Giancoli 6th edition, where they never really define it ). I just want to get a handle on the concept in general. Thanks ~

See the "Gauss's Law Sketch Proof" paragraph .[/URL] Griffiths uses mainly the same argument to prove Gauss's law, but I don't really see the connection between the fact that the flux is Q/epsilon for a sphere and the conclusion that it is worth this quantity too for any closed surface. Can...

Can someone give me a couple hints to get me started on this problem, I am not sure where to go next. Infinite line of charge has charge per unit unit length 4.8*10^-6 and lies along the x axis. A second uniform line of charge with charge/unit length -2.4*10^-6 is parallel to the x-axis at...

An infinitely long solid cylinder radius R1 lies with it's central cylindrical axis lying along the x axis. it is made of a non-conducting material. It has a volume charge density that varies with readius as follows... p(r)=A.r (C/m^3) where A is a constant. Consider a cylindrical Gaussian...

Hey everyone, this is my first question on here, but I've seen you all be very helpful to others to I was hoping someone could clarify something for me. 1. How does Gauss law modify in dielectric materials?

Problem : A long coaxial cable carries a uniform volume charge density \rho on the inner cylinder (radius a ), and a uniform surface charge density on the outer cylindrical shell (radius b ). The surface charge is negative and of just the right magnitude so that the cable as a whole is...

Gauss's Law HELP! I need some help with Gauss's Law. In the book it states that if you have an irregular shape, then you can project each piece of that irregular shape onto a sphere. And since a sphere has field lines everywhere perpendicular to it, it makes life very simple because the flux...

I'm encountering a problem with a practice test and previous homework problem in my electrostatics class. Charges exist at three corners of a square as shown. Edge length = L. What is the Electric Field Strength (E) at the corner with no charge. -3q O------------O +2q...

Hello, I was wondering if anyone has any links to any Electricity & Magnetism tutorials. I don't understand very well and was hoping for maybe an online book or something. Our lecture textbook sucks. We are doing Gauss's Law. Thanks!

First I set about to calculate the electric field: Solve for Q with the capacitance of two coaxial cylinders: substituting: Where 'r' is a distance measured from the center. Trying several distances (r = 5cm -> E = 69.2 Volts / meter, r = 2cm [on the internal cylinder] -> 432.8 Volts...

Here is the problems that's giving me trouble: Positive charge Q is distributed uniformly over each of two spherical volumes of radius R. One sphere of charge is centered at the origin and the other at x=2R. Find the magnitude and direction of the net electric field due to these two...

Here's the homework problem I'm having trouble with: A solid metal sphere of radius .4 m carries a net charge of .190nC. Find the magnitude of the electric field at a point .130 m outside the surface of the sphere. I used the equation EA=q/Epsilon_0 E(4*pi)(r^2)=q/Epsilon_0...

I can't seem to figure out how to apply Gauss's law to a uniformly charged cube(side length a), charge density = rho = Q/a^3. Here's the problem: I have a uniformly charge cube, of side length 'a,' with total charge Q which has a conductor on two oppossing faces. I want to know the electric...