Electric potential Definition and 1000 Threads

Given the following problem: An electric dipole has charge +Q at position a and charge –Q at position -*a along the z axis. a. Calculate the electric potential at an arbitrary point. Choose the arbitrary constant so at V=0 at infinity. Express the result in terms of r and θ (radius and polar...

Homework Statement An electric field is given by E = 2xi-3y2j N/C. Find the change in potential from the position rA = i - 2j m to rB = 2i + i + 3k m. Homework Equations VB - VA = -\int_A^B E\cdotds The Attempt at a Solution ΔV= -\int_1^22x dx - \int-3y^2 dy The second...

Homework Statement A cross-section of a cylindrical high voltage terminal (inner cylinder) of a van de Graaff generator, surrounded by an 'intershield' (middle cylinder) and a pressure vessel (outer cylinder). The gas in the pressure vessel breaks down in electric fields greater than...

Homework Statement Suppose you wish to determine Ka for a monoprotic weak acid of molecular mass 76.11 g/mol. The pH meter you need to use is not working. You decide to weigh out 2.28 g of the acid and 1.96 of its sodium salt and dissolve them together in water, add quinhydrone and set up a...

Homework Statement There are three charges q1, q2 and q3 situated at corners of a rectangle of sides a = 15.0 cm and b = 8.0 cm. For q1 = 4.90 μC, q2 = -4.90 μC, and q3 = 1.50 μC a) find the electric potential at the center of the rectangle. b) Continuing with the system above...

I am totally lost about the idea of electric potential and work. sometimes the book defines work as negative and sometimes postive. please explain

Homework Statement Suppose we there is a cube (a x a x a) made up of 8 protons. 1 at each point What is the Electric Potential Energy Homework Equations U=q1*q1/4*pi*epsilon_0*r The Attempt at a Solution *U12 = Potential Energy to bring 2 to 1* I'm aware of how to do the...

A uniform electric field has a magnitude 2.40 kV/m and points in the +x direction. (a) What is the electric potential difference between x = 0.00 m plane and the x = 3.90 m plane? (b) A point particle that has a charge of +3.40 µC is released from rest at the origin. What is the change in the...

Homework Statement I understand the concept of negative potential energy value because it's chosen to be 0 at infinity. So considering two positive charges, as separation r increases, the potential energy V decreases. When there's one positive and negative charge, as r increases, V...

basically i don't understand the basic main idea of electric potential energy. since by definition, energy is ability to do work( to move an object across a distance). Negative source charge creates a uniform field around itself, and we place a positive test charge very near the source...

Hi, I was conducting an experiment on a material using XRD and I investigated two cases. One case is the presence of outside electric potential, that is, the material being connected to a electric circuit. The other case is the absence of this electric potential. I found that the two XRD...

Hi, I was conducting an experiment on a material using XRD and I investigated two cases. One case is the presence of outside electric potential, that is, the material being connected to a electric circuit. The other case is the absence of this electric potential. I found that the two XRD...

Homework Statement As a +6.2-µC charge moves along the x-axis from x = 0 to x = 1.4 m, the electric potential it experiences is shown in the figure, below. (The horizontal axis is marked in increments of 0.1 m and the vertical axis is marked in increments of 5 V.) Find the approximate...

Homework Statement A solid sphere of radius R has a uniform charge density ρ and total charge Q. Derive an expression for its total electric potential energy. Suggestion: Imagine that the sphere is constructed by adding successive layers of concentric shells of charge dq = (4\pi r^{2} dr) ρ...

Homework Statement A proton is released from rest in a uniform electric field of magnitude 40000V/m di- rected along the positive x axis. The proton undergoes a displacement of 0.3 m in the di- rection of the electric field The mass of a proton is 1.672623×10−27 kg A.Find the...

Homework Statement A) How much work would it take to push two protons very slowly from a separation of 2.00*10-10 m (a typical atomic distance) to 3.00*10-15 m (a typical nuclear distance)? B) If the protons are both released from rest at the closer distance in part A, how fast are they...

Homework Statement A rod of length L has a total charge Q uniformly distributed along its length. The rod lies along the x-axis with its center at the origin.What is the electric potential as a function of position alon gthe x-axis for x>L/2 Homework Equations V=∫kdq/r = ∫kQ/r dx I'll...

Homework Statement Consider 2 infinite parallel thin sheets of charge, one in the x=0 plane and the other in the x=a plane. The potential is 0 at the origin. Find the electric potential everywhere in space if the planes have equal positive charge densities of +omega. I honestly don't even...

Since V is the integral of -E. Shouldn't E be derivative of -V. I asked my TA that and he said something about them not having that kind of a relationship, can someone explain this?

Homework Statement Find the electric potential at a point d perpendicular to one end of a line of charge with a positive uniform linear charge density lambda, length L, and negligible thickness. Homework Equations EdA=q/ε_0 A = 2πdL V_f - V_i = -integral(Eds) The Attempt at...

Electric potential is the work done in moving a unit charge from infinity to a point in an electric field. Electric potential due to point charge: V=-\int \vec{E}\cdot d\vec{s} V=-\int E\cdot ds cos \vartheta if the stationary charge is positive and if the test charge is is moved from...

I'm trying to find the electric potential inside a thin (not charged) spheric conductor of radius R, containing a point charge of charge +q exactly in the center. To do this, I'm trying to solve the differential equation \Delta V = 0 (harmonic). Together with the boundary condition V(R) = c...

Hello, in this diagram, the shaded regions are spherical conductors. What's the potential at A=B? Ignoring the outer sphere, it should be kQ/R. When you add the outer sphere, potential at C=D=0 and electric field between B and C is kQ/x^2 so i integrated (kQ/x^2) dx with interval [2R, R]...

Homework Statement For this exercise, imagine a large positive charge +Q fixed at some location in otherwise empty space, far from all other charges. A positive test charge of smaller magnitude +q is launched directly towards the fixed charge. Of course, as the test charge gets closer, the...

Homework Statement Calculate the electric potential due to a tiny dipole whose dipole moment is 6.0×10^−30 C*m at a point 3.6×10^−9 m away for the following cases. a) This point is along the axis of the dipole nearer the positive charge. b) This point is 45 degrees above the axis but...

Homework Statement a large positive charge +Q fixed at some location in otherwise empty space, far from all other charges. A positive test charge of smaller magnitude +q is launched directly towards the fixed charge. Of course, as the test charge gets closer, the repulsive force exerted on...

Hi , am a computer science student , am newbie at physics , and am train to learn but no help , though i took a course in [physics 1] before 3 yrs and i can't remember anything, and now i am taking physics 2 , i took so far , electric fields , Gauss law ,Electric potential , capacitance . book...

Homework Statement A -14.3 nC point charge and a +24.9 nC point charge are 17.4 cm apart on the x-axis. What is the magnitude of the electric field at the two points on the x-axis where the electric potential is zero? Homework Equations V = kq/r E = kq/r^2 The Attempt at a...

Homework Statement A conducting sphere of radius r1 = 10 cm and charge q1 = 2 µC is placed far apart from a second conducting sphere of radius r2 = 30 cm and charge q2 = 3 µC. The two spheres are then connected by a thin conducting wire. What is the potential on the surface of the first...

Hi Forum! I have got a question about the induced scalar potential. I will present the problem from beginning. Lets say we have a Poisson's equation in form: \epsilon \nabla^2 \phi = -4\pi \varrho(r,t) where \epsilon is the dielectric constant. By use of the Fourier transform...

If you look at the diagram right below the headline "Electric potential diagrams" in http://www.physicsclassroom.com/Class/circuits/u9l1c.cfm" (about halfway down), you can see that in circuit A, the electric potential at point A is the same as that at point B, and likewise for points C and D...

Homework Statement . A wire of finite length that has a uniform linear charge density λ=6.22×10-9 C/m is bent into the shape shown below. [PLAIN]http://lulzimg.com/i23/7498af.jpg Answer: 2.98e+02 VHomework Equations V = k integral (dq/r)The Attempt at a Solution So i think my integrals are...

Hi all, I am trying to run a simulation, and I have come across a theoretical question. Let's say that you have an electric charge producing a potential on a conducting surface (let's assume it's infinite). Now, if you make a crack in the surface so that there is a gap (filled with air for...

Homework Statement So here is the problem: http://i.imgur.com/IlklC.png" I already know the answers but I can't figure out why it is the case. How do you know when the forces cancel out? Homework Equations The Attempt at a Solution The answers should be: a) 1,2 b)None c)...

Homework Statement Let there be an infinite plate of positive charge density σ. Let there also be an uncharged conducting slab of a thickness h, placed above and parallel to the plate. Without copying the question directly, I would like to know how one would calculate the electric...

I'm currently reading on my own on these topics for the first time in Fundamentals of Physics by HRW. Electric charge, electric fields, and Gauss' Law were 3 hard chapters, but manageable. In this chapter certain aspects aren't really clear to me at all, and there is more math than physical...

Why is it that we assume electric potential to be continuous across boundaries in electrostatics problems (like, say we have a situation with concentric spheres with different equations for electric field across boundaries)? This is the case as far as I've seen at least. I am in introductory E&M...

Homework Statement A thin rod stretches along the z-axis from z = -d to z=d as shown. Let lambda be the linear charge density or charge per unit length on the rod and the points P1 = (0,0,2d) and P2 = (x, 0, 0). Find the coordinate z such that the potential at P1 is equal to that at P2...

Homework Statement We have an infinitely-long perfect electrical conductor (PEC) cylindrical core (Region 3) of radius a surrounded by a dielectric layer (Region 2) of permittivity ε2 and radius b. The combined conductor/dielectric cylinder is embedded in an infinite space (Region 1) of...

Why is electric potential (voltage) necessary? I can see how creating the electric field as the force per unit charge allows the force on one charge in the field of another charge to be calculated and accounts for the observed action at a distance by forces. I don't see the correlation of...

Homework Statement The plastic rod of length L shown in the figure has the nonuniform linear charge distribution λ =cx, where c is a positive constant. Find an expression for the electric potential at point P on the y-axis, a distance y from one end of the rod. V = ?Homework Equations V = 1/4πϵ

Homework Statement A 5.5 cm radius conducting sphere is charged until the electric field just outside its surface is 1667 V/m. What is the electric potential of this sphere, relative to infinity? Homework Equations V = - integral ( E (dot) dl ) The Attempt at a Solution They only...

Hi all, What is the potential generated by a electric loop? I have found two ways to sovle the problem. One is since the charge density does not change with time, we can write it as \phi(\vec{r_{0}})=\oint\frac{\rho_{static}}{|\vec{r}-\vec{r_{0}}|}d\vec{l}. But what is \rho in this loop? Is...

Homework Statement There are four uniformly charged rods of linear charge density \lambda and length a, arranged as a square. What is the electric potential a distance z from the center of the square and along the symmetrical axis? The Attempt at a Solution...

Homework Statement A charge of +6.0µC at point A is separated 10.0 cm from a charge of -2.0µC at point B. At what locations on the line that passes through the two charges will the total electric potential be 0? The Attempt at a Solution[(+) A] ------------------------------ [(-) B]I know that...

Homework Statement What is the electric potential at the point indicated with the dot in the figure? http://img842.imageshack.us/i/29ex26.jpg/ Homework Equations E = V_c / d ? V = E*s? V = k * q / r ? The Attempt at a Solution I'm really rather confused by this problem...

Homework Statement "Two point charges 2.0cm apart have an electric potential energy -180 microJoules. The total charge is 31 nC. What are the two charges?" Homework Equations V= k * q / r The Attempt at a Solution I understand that V = -180 * 10^-6, k = 9*10^9, r = 0.02m, and the...

Homework Statement A proton is released from rest in a uniform electric field of mag. 90000 V/m directed along the positive x axis. the proton undergoes a displacement of .2m in the direction of the electric field. Find the change in electric potential. Homework Equations no idea...

Homework Statement Which of the following statements about the electric potential inside a metal object are correct? Check all that apply. The potential at any point inside a metal at equilibrium is equal to the potential at the surface, which may be nonzero. The potential is the same...

Homework Statement write down an expression for the electric potential of an electric dipole at a large distance Homework Equations V=(qa cos(theta))/(4 pi epsilon r^2) The Attempt at a Solution is 'r' the distance they are talking about or is it 'a'? either way, if i substitute in...