Electric potential Definition and 1000 Threads

Homework Statement The potential outside of a spherical conductor is given by V = keQ/r. Using Er = -dV/dr, derive the electric field outside this charge distribution. The Attempt at a Solution I attempted to take the negative derivative of V being -1/(r2) and then multiplying it...

Homework Statement The four 2.23 g spheres shown below have q+ve=15.0 nC and d=3.28 cm. The spheres are released simultaneously and allowed to move away from each other. What is the speed of each sphere when they are very far apart...

This is more of a question about a concept than the actual homework problem. The homework problem gives diagrams of rods with varying charge densities, but there's one important concept I don't yet understand, and it's stopping me from moving on in the problem. My question is even more...

Homework Statement An electron is released from rest on the axis of a uniform positively charged ring, 0.174 m from the ring's center. If the linear charge density of the ring is +0.150 nC/ m and the radius of the ring is 0.348 m, how fast will the electron be moving when it reaches the center...

1. Homework Statement [/b] Consider two thin, conducting, spherical shells as shown in cross-section in the figure below. http://capa.physics.mcmaster.ca/figures/sb/Graph25/sb-pic2565.png [b] The inner shell has a radius r1 = 17.2 cm and a charge of 10.3 nC. The outer shell has a radius r2 =...

Homework Statement Two concentric spherical conducting shells of radii a = 0.360 m and b = 0.540 m are connected by a thin wire, as shown in the figure below. http://capa.physics.mcmaster.ca/figures/sb/Graph25/sb-pic2550.png If a total charge Q = 10.6 µC is placed on the system, how much...

I'm not understanding how the equation of the electric field due to an electric dipole is derived. This is how my book derives it: Say you have electric dipole composed of charges +q and -q a distance d apart, with the negative charge at the origin of the z-axis. Then, at any point z, the E...

Homework Statement 10. If an electron is released from infinity, how fast will it be traveling after falling to within 10-8m of a charge q of 4.8*10-19? a. 1.32*104m/sec b. 8.7*104m/sec *c. 2.76*105m/sec d. 4.01*105m/sec Homework Equations ΔU=ΔVq V=kq/r conservation...

Homework Statement Two charged spherical conductors are connected by a long conducting wire, and a charge of 22.0 µC is placed on the combination. If the first sphere has a radius of 4.49 cm and the second has a radius of 5.68 cm, what is the electric field near the surface of each sphere...

Homework Statement Two charges q = 4.0μ C are fixed in space a distance d = 4.0 cm apart, as shown in the figure. With V = 0 at infinity, what is the electric potential at point C? You bring a third charge q = 4.0μC from infinity to C. How much work must you do? What is the potential...

Homework Statement Examine the diagram provided, Sphere 1: q=3.0x10-4C Sphere 2: q=-3.0x10-4C Sphere 3: q= 3x10-4C a) Find the total electric potential energy of the charge distribution b) Find the total electric potential at point Z Homework Equations EE=kq1q2/r...

Homework Statement Find the strength of the electric field midway between two point charges, q1=5.78nC and q2=-5.78nC separated by 68cm. Homework Equations Kq1q2/r2=F \epsilon=F/q The Attempt at a Solution I just tried the problem as a two step equation but it's giving me a huge...

Homework Statement What's the difference between electric potential energy and electric potential? Can someone explain these concepts, simply? I don't understand any definitions I've found on the internet. Any help would be appreciated. Homework Equations N/A The Attempt at a Solution N/A

Homework Statement Two frictionless pucks are placed on a level surface as shown, at an initial distance of 20m. Puck 1 has a mass of 0.8 kg and a charge of + 3x10^-4 while puck 2 has a mass of 0.4 kg and a charge of +3 x10^-4. The initial velocity of puck 1 is 12 m/s [E] and the...

hello , I want to get the electric potential function with displacement V(x,y,z) as Ex= -8 -24xy Ey =-12x^2+40y Ez= zero when I perform intergration on Ex and Ey seperately then sum them , the answer is wrong , why ?? I mean when I do this and then perform partial derivatives again ...

Homework Statement A +3μC charge with a mass of 2 x 10 ^-4 kg is moving with a speed of 5 m/s at a position where the electric potential is 1000 V. How fast will it be moving when it gets to a position where the electric potential is 200 V? Assume energy is conserved. Homework Equations...

Electric potential --- doubt in sign convention Homework Statement Revered members, I know dV = -E.dx so E = -dV/dx So E should be E = -V/x . But while deriving capacitance of a parallel plate capacitor when dielectric medium is introduced we use E = V/x. But how E = V/x? Homework...

When we setup the Schrodinger equation for the hydrogen atom we use the classical electric potential. It seems that we would need a new potential instead of mixing QM and classical. Is this just a very good approximation or is there something subtle.

Say we have a spherical shell of outer radius b and inner radius a. The shell has a total charge +3q and at it's center is a point charge of charge -q. I know that the E field for r>b would simply be: E = (3q-q)/(4πr^2ε0) and thus the electric potential inside the shell must be the same as the...

What will be the total electric potential energy of two concentric spheres. Will it be = [P.E. of Inner sphere] + [ P.E. of Outer sphere] + [ Energy required to bring outer sphere from infinity to the present position(i.e. position concentric to inner sphere) ] OR it Will...

I am confusing about dealing with the vectors in integral boundaries of the electric potential; ^{b}_{a}∫E.ds where a and b are vectors. For example, if I would calculate the potential for outside region of a sphere along z-direction, I would use E=\frac{ρR^3}{3ε_{0}z^2}\hat{z}, and...

A hollow metalic cylinder of radius r and length l, has potential V0 over its surface. The axis of the cylinder coincides with the z axis, and the cylinder is centered at the origin. The cylinder is placed paralel(the electric field parallel with z axis) to an otherwise uniform electric field E...

Homework Statement Find the electric potential inside and outside a spherical capacitor, consisting of two hemispheres of radius 1 m. joined along the equator by a thin insulating strip, if the upper hemisphere is kept at 220 V and the lower hemisphere is grounded Homework Equations...

yes, energy = work, but how does electric potential energy (U) = Vq (electric potential and charge) relate to work (W=Fd), specifically. An example would be most helpful!

Homework Statement calculate the electric potential for the following: A cylindrical cable with a center rod of diameter a surrounded by a gap and a thick pipe with inner and outer radii b & c. The charge distribution on the inner rod is ρ = k cos(sπ/2a), and the outer rod has a uniform...

Homework Statement How do I calculate the Field Strength if I know the Potential? Homework Equations E = -\nablaV V = Electric Potential E = Electric Field Strength The Attempt at a Solution There's a problem in which I calculated the Potential, it's constant however. So according...

1. Electric potential inside a conductor / outside a coaxial cable Electric Potential inside a conductor(spherical) is a constant, although electric field is zero. How does that make sense given: Given V=- \int E \cdot dl? The integral should be 0. Even if you consider constants of integration...

Homework Statement The electric potential immediately outside a charged conducting sphere is 250 V, and 10.0 cm farther from the center the magnitude of the electric field is 440 V/m. (c) Determine all possible values for the radius of the sphere. (Enter your answers from smallest to...

Δv=v? what is the electric potential in a conductor? LETS set the conductor be a shell carrying charge 15nC, then what is the electric potential inside the conductor? should it be just finding v=kq/r? Or we have to find the Δv? Thanks

Homework Statement What should I do when I calculate the potential of point charges at the point of one of the point charges? Homework Equations The definition of a potential from point charges are: \phi(\textbf{r}) = (4\pi \epsilon_0)^{-1}\sum_{i}[q_i...

Homework Statement I have an expression for electric potential. Can I multiply this by mass to turn it into potential energy? Homework Equations W=Fs ? The Attempt at a Solution

Homework Statement At a certain distance from a point charge, the magnitude of the electric field is 500 V/m and the electric potential is -3.00 kV. (a) What is the distance to the charge? (b) What is the magnitude of the charge? Homework Equations The Attempt at a Solution a) 6 meters b)...

Excuse me, may i know how should one calculate the electric potential of two conductors placed together? one inner sphere(radius a) together with another outer shell(radius b). Why is the "electric potential between the sphere and shell" equal to the electric potential in the sphere? LEts put...

Homework Statement In an imaginary sphere with radius R, there exist uniformly distributed space charge ρ. Find the potential in all points in space, bounded by this sphere. (r<R). Dielectric is air. ******Must use Poisson or Laplace equation****** Homework Equations \nabla\cdot\nabla ={\Large...

Ignore this. How does one delete a post?

I'm given the following problem: A particle with charge q is located at x=-R and a particle with charge -2q is located at the origin. Prove that the equipotential surface that has zero potential is a sphere centered at (-4R/3,0,0) with radius r=2/3R. I started by dividing the length between...

Find the electric potential for an axial quadrupole: point charges q, -2q, q over the z axis at distances l,0,l from the origin. Find the electric potential only for distances r>>l and demonstrate that the potential is proportional to one of the zonal armonics. Well, I found at wikipedia that...

Hey, So I pretty much don't understand why certain concepts work when dealing with electric potential. Suppose we have an infinite plane with some positive charge density, and the magnitude of the E field at an distance z from the plane is defined as E = (σ)/(2ε) (so the field is uniform...

We have a piece of a cylinder of infinite length and radius R, charged with a uniform and positive volumetric density of charge p. Compute: a) Difference of electric potential between the axis of the cylinder and its surface. b) Work to carry a charge q from the axis to the surface of the...

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...