Electric potential Definition and 1000 Threads

Alright, so there is a very basic theory involving capacitors and electric potential that is throwing me off. I have a very basic problem here: http://img444.imageshack.us/img444/2251/73619554.png Assume the switch is closed and the capacitor is fully charged. From here I'm prompted to find...

Homework Statement Calculate potential.

A Particle of charge q=7.5x10^-6 Coulombs is released from rest at .6m on the x axis. The particle moves due to charge Q = -20x10-6 C. What is the Kinetic Energy of the particle the instant it has moved .4 meters if Q stays fixed at the origin? Here I used KE1 + U1 = KE2 + U2 Which equals 0 +...

1. Find the electric potential inside and outside a uniformly charged sphere of radius R, and whose total charge is q. Use infinity as your reference point. Compute the gradient of V in each region and check that it yields the correct field. Sketch V(r). 2. I used the theorem that electric...

Homework Statement Hi everyone, I'm supposed to find an expression for the electric potential as a function of r, the radial distance inside a solid and non conducting sphere of radius R. A total charge of q is uniformly distributed throughout its volume. The annoying part is that I'm supposed...

I have some difficulties grasping the idea of this equation W[SIZE="1"]p = q * E * r Where W[SIZE="1"]p - electrical potential energy q - charge E - the strength of the electric field r - radius, or distance from the other point charge So basically, say we have 2 point charges. One...

Homework Statement What are (a) the charge (in C) and (b) the charge density on the surface of a conducting sphere of radius 0.21 m whose potential is 290 V (with V = 0 at infinity)? Homework Equations v = kq/r \sigma = q/SA SA of a sphere = 4\pir^2 The Attempt at a Solution so...

Calculate electric potential at A, 3.0 m away from a point charge of +1.0 C Calculate the electric potential at B, 6.0 m away from a point charge of +1.0 C How much work would be done moving a +0.2 C charge between A and B I'm not sure what equation/s to use?

Two metal spheres are connected by a long wire with a switch. The radius of the larger sphere (B) is b= 0.20 m and the radius of the smaller sphere (A) is a= 0.080 m. Initially the switch is open and both spheres have zero charge. Then charge Q0 = 1.0 μC is placed on the larger sphere. B)...

Hello, I am having trouble in proving the equation of the electric potential near a point charge Q. There are two different ways I can think to go about deriving the equation V=q/(4*Pi*E0*r). The first way is to calculate the change in potential energy of a test charge q0 in coming from...

QUESTION 1 Homework Statement Two positive charges, each with Q = +10 µC, are fixed to the x-axis at x = +a and x = -a, where a = 4 m. (a) Find the electric potential at point A on the y-axis where (xA, yA) = (0, b) and b = 5 m. Take the zero of potential to be at infinity. (b) A...

Homework Statement I need to prove that the formula for electric potential (V) of a charged disc (with radius r) and with a uniform charge density, that V=2kpisigma\(sqrt{x^2+r^2}-x) when x is very large compared to r, and Q is the total charge of the disk, that this formula reduces to...

Homework Statement I am basically given a cone with uniform volume charge and told to find the area of highest electric potential. Homework Equations I want to use the equation: V= q/4piEr The Attempt at a Solution I am having trouble finding anything in my book. I am comparing...

Homework Statement The drawing shows a uniform electric field that points in the negative y direction; the magnitude of the field is 3000 N/C. Determine the electric potential difference (a) VB - VA between points A and B, (b) VC - VB between points B and C, and (c) VA - VC between points C...

A sphere of radius r contains a charge Q distributed uniformly throughout its volume. Charge dQ is brought in from infinity and deposited uniformly over the surface. The potential energy of the charge dQ is Q dQ/4\pi\epsilon0. This follows naturally from the result for the potential of 2 point...

Homework Statement I know the definition of electric potential is the work done to bring a test charge from infinity to a particular point. But I read about some question asking the electric potential of a charged conductor, I wonder what that means, whether it is the potential of the surface...

Electric Potential Problem Assistance! Homework Statement There is an equilateral triangle with one point charge at each vertex. The point charges have charges of -Q, +3Q and -4Q respectively. The length of one side of the triangle is L. Determine an expression in simplest form for the...

I was wondering for a series of capacitors connected together (after full charging), is there a voltage difference between the negative plate of one capacitor and the positive plate of another capacitor down the line? -------+q||-q(a)-------+q(b)||-q------+q||-q---------- i.e. between points...

Homework Statement A plutonium-239 nucleus, initially at rest, undergoes alpha decay to produce a uranium-235 nucleus. The uranium-235 nucleus has a mass of 3.90 * 10-25 kg, and moves away from the location of the decay with a speed of 2.62 * 105 m/s. Determine the minimum electric...

Homework Statement Consider the circuit in the figure below, in which C2 = 16 µF and V = 80 V. Initially, the switch in is in position A and capacitors C2 and C3 are uncharged. Then the switch is flipped to position B. Afterward, what are the charge on and the potential difference across...

Homework Statement A charge of –4.00 µC is fixed in place. From a horizontal distance of 55.0 cm, a particle of mass 2.50 × 10–3 kg and charge –3.00 µC is fired with an initial speed of 15.0 m/s directly toward the fixed charge. How far does the particle travel before it stops and begins to...

Homework Statement A proton is released from rest at point A in a constant electric field and accelerates to point B (see part a of the drawing). An electron is released from rest at point B and accelerates to point A (see part b of the drawing). How does the change in the proton's electric...

Homework Statement Three equal point charges, each with charge 1.95 nanoC , are placed at the vertices of an equilateral triangle whose sides are of length 0.550m . What is the electric potential energy of the system? (Take as zero the potential energy of the three charges when they are...

Electric Potential ! Am getting confuse with the definition, why does the definition says "workdone is bringing unit POSITIVE charge from infinity to that point" and not NEGATIVE charge? can it be negative also in the definition or is it because we always use positive test charge...

Hello, I just read on "Integrated electronics" by Millman the following definition: "The potential V (volts) of points B with respect to point A is the work done against the field in taking a unit positive charge from A to B. For a one-dimensional problem with A at x_0 and B at an arbitrary...

Homework Statement A wire has a resistance of 0.010 ohms. What will the wire's resistance be if it is stretched to twice its original length without changing the volume? Homework Equations R = pL/A The Attempt at a Solution R = p(2L)/A pL/A = R/2 =0.010/2 =0.0050 ohms...

Homework Statement A -3.0 nC charge is on the x-axis at x = -9cm and a +4.0 nC charge is on the x-axis at x = 16 cm. At what point or points on the y-axis is the electric potential zero? Homework Equations V = kq/r The Attempt at a Solution I know the answer is +/- 12 cm but I...

is electric potential conservative? is it correct?

Homework Statement A -2.0 nC charge and a +2.0 nC charge are located on the x-axis at x= -1.0 cm and x = 1.0 cm, respectively. At what position or positions on the x-axis is the electric potential 0? Homework Equations V = kq/r The Attempt at a Solution I'm having difficulty...

Homework Statement There are four points. The electric potential difference between points 1 and 2 (V12) is 30V, the electric potential difference between points 2 and three (V23) is 50 V, and the electric potential difference between points 4 and 1 (V41) is 60 V. What is the electric...

Hi Ok so i came across this question which asks you to find the force on electrons in a wire which is moving in a magnetic field, hence the opposite to the direction of the current. I worked out using The right hand rule that the current would be going from point P to Q, which was write...

Homework Statement What is the difference in electric potential between a point midway between the charges and a point 0.05 meters away from the positive charge but along the line between the charges? Homework Equations UE = K * (Q1*Q2)/r The Attempt at a Solution K = 9.0x109Nm2/C2 UE =...

Hi I am sure this is very basic but i am struggling to derive or work this out, and i have looked, on the internet and textbooks and can't find this. The electric potential at a point is defined as the work done per unit charge to move a small test charge from infinity to that point...

Electric Potential Energy Among Multiple Charges kinda aurgent [b]1. Homework Statement Four point charges, fixed in place, form a square with side length d. (See image) http://i23.photobucket.com/albums/b354/h4llw4x0r/notSoFast.jpg The particle with charge q is now released and given...

Hi =D I know that the electric potential in any given point (considering only a point charge) in a region is defined to be: \varphi = \frac{q}{4\pi \varepsilon_{0} d} I know too that the electric potential generally can be defined as: \varphi = - \int_{P1}^{P2} \overrightarrow{E}...

When I hold voltmeter contacts in my hands, (one in each) the meter reads about .2V I know it isn't that significant, but what could be the explanation for this? Are we charged? Why would there be potential between my left and right hand? Or is it just a fluke from rubbing my socks on the...

We say that if pint A is at a higher potential than point B, A is at positive potential and B is at negative potential. Does it necessarily follow that a point at positive potential is positively charged, or that a point at negative potential is negatively charged? Why?

Homework Statement I'm confused about the correlation between electric potential and electric field. Does a high electric potential mean the electric field is also high? Homework Equations E=-(dV/dx, dV/dy, dV/dz) and V(x)=V0 - E x The Attempt at a Solution I think not...

[PLAIN]http://img526.imageshack.us/img526/5079/29693720.jpg im struggling to start this question do i calculate all of the potentials seperatly and add them up? and to calculate the potential on the circle and 1/4 circle would i just use 2pi r ? and for the 1/4 cirlce definite intergrate it...

my teacher gave me a handout that said Vab = Vb- Va However my textbook says Vab = Va-Vb.. Which one is correct? By the way Va means voltage at a and Vb equals voltage at b

Homework Statement An electrically neutral conducting sphere of inner radius Ra and outer radius Rb is centered on the origin. Two equal, positive point charges of magnitude Q are located on the x-axis on each side a distance d from the origin. Determine the electrical potential in the...

Homework Statement Point P is at the origin. Charge A is at (-3,0) and Charge B is at (4,0). What is the electric potential at point P. Let's assume they are both positive charges for now, but I am interested to know if and how it changes if either/both of the charges are negative...

how would you solve this problem? A charge q1 = 3.40 nC is placed at the origin. Three identical charges, q2, q3 q4, are placed at the positions (0.100 m, 0 m), (0 m, 0.100 m), and (0.100 m, 0.100 m). What is the potential energy of this configuration of charges? should you do answer =...

A proton's speed as it passes point A is 53,000 m/s. It follows the trajectory shown in the figure below, in which V1 = 15 V and V3 = 5 V. What is the proton's speed at point B? Figure: http://www.webassign.net/knight/p29-44alt.gif Homework Statement Mass of proton: 1.67e-27 Charge of...

1. Two point charges 2.0cm apart have an electric potential energy -180 microjoules. The total charge is 30 nanocoulombs. What are the two charges? Givens: change in postition = 0.02m , Q = 30nC = 3.0e-8C, V = -180 microjoules = 1.8e-4 Homework Equations F = kq1q2/r^2 E = kq/r^2 The...

ok, the electric field E = - dV / dx, where V is the potential. but what is exactly is x? because i am quite confused by E and V why is it that the electric field E is = 0 IN a conducting charged sphere of radius R, AND V = k (q/R) , WHEREAS, the electric field E is = 0 IN a long...

Homework Statement The wire in the following figure has linear charge density \lambda. What is the electric potential at the center of the semicircle? Homework Equations The Attempt at a Solution I can see a lot of integration going on here, but i am having trouble the setup the...

Homework Statement The figure shows a thin plastic rod of length L = 11.8 cm and uniform positive charge Q = 58.9 fC lying on an x axis. With V = 0 at infinity, find the electric potential at point P1 on the axis, at distance d = 3.45 cm from one end of the rod...

Homework Statement Consider charges placed at the corners of a rectangle. This rectangle is a horizontal rectangle and is .43 m long and .25 m wide. At the upper right corner there is a charge of 7.0 µC. At the bottom right there is a charge of -14 µC. At the bottom left there is a charge of...

A plastic rod with a total charge Q uniformly distributed along its length is bent into a regular hexagon where each side has a length of 2a, as shown below. Calculate the electric potential at the center of the hexagon (relative to the point at infinity). I wasn't sure how to exactly start...