Point charge Definition and 345 Threads

http://www.monmsci.net/~fasano/phys2/Chap22_10.pdf The question is on this PDF File. It's 22.8. I get the logic of it, the electric fields will be 0 only when they both have the same magnitude. The math is shown below the problem, but i don't understand it. Could someone solve this and show me...

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...

Homework Statement We have a metal conducting torus and a point charge that is located on the torus' axis (location on the axis is arbitrary). Calculate the (influenced) charge distribution on the torus and the electrostatic force on the point charge. Homework Equations Equation for...

Hi everyone, I took a look at previous questions similar to this one and it seems like I am doing everything correctly, but I still get the wrong answer. Any advice to where I am going wrong would be greatly appreciated!Homework Statement A point charge (m=1.0g) at the end of an insulating...

My questions are what the book said after working out the solution that I have no issue of finding. The original question is to find E and B at a field point pointed by r due to a moving point charge pointed by w(t_r) at retard time moving at a constant velocity v. For constant velocity...

The electric field at a point P pointed by the position vector \vec r \;\hbox {, from a moving point charge pointed by a position vector }\;\vec w(t_r)\; at the retarded time is given by: \vec E_{(\vec r,t)} = \frac q {4\pi\epsilon_0}\frac{\eta}{(\vec{\eta}\cdot \vec u)^3}[(c^2-v^2)\vec u +...

Homework Statement Use V=kq/r, E(x) = V/x, E(y) = V/y, E(z) = V/z to derive an expression for the electric field at a point charge q. E(r) = ? Homework Equations E= F/Q

Homework Statement Use V=kq/r, E(x) = V/x, E(y) = V/y, E(z) = V/z to derive an expression for the electric field at a point charge q. E(r) = ? Homework Equations E = F/Q

Homework Statement what is the magnitude or a point charge whose electric field 50cm away has the magnitude 2nc? Homework Equations E=1/4pi.epsilon sub zero q absolute/r sqrt2 1/4pi.epsilon sub zero=8.99x10sqrt9 The Attempt at a Solution that gives me 71.92 and my solution in the...

Homework Statement Two particles are fixed to an x axis: particle 1 of charge q1= 2.1 * 10^-8 and particle 2 of charge q2= -4.00q1 at x=70 cm. At what coordinate on the axis is the net electric field produced by the particles equal to zero? Homework Equations Enet = E1 + E2 E=F/q F=k...

1. A rod 16.0 cm long is uniformly charged and has a total charge of -24.0 µC. Determine the magnitude and direction of the electric field along the axis of the rod at a point 36.0 cm from its center. 2. How is this problem done? 3...

This is part of the problem in the exercise to find charge distribution of a point charge at origin. I know \nabla \cdot \vec E = \frac {\rho}{\epsilon_0} \rho = \epislon \nabla \cdot \hat r \frac q {4\pi\epsilon_0 r^2} \;\hbox { where } \vec r = \hat x x + \hat y y + \hat z z \nabla...

I've got a test coming up on this, and got quite a few of the questions on the related homework wrong. Attached is the problem, my solutions, and the book(correct) solution, please try to find what I'm doing wrong, this is driving me nuts. Homework Statement Two charges exist along the...

Homework Statement A charged particle is fixed in place at the origin. A second particle of charge +10^{-6} C is released from rest from very far away (\approx (\infty, 0)). The second particle passes the point (9 m, 0) with a kinetic energy of 1.0 J. Find the electric potential due to...

1. Three equal positive point charges of magnitude Q = 5.00μ C are located at three corners of a square of edge length d = 7.8 cm. A negative charge -15.00μ C is placed on the fourth corner. At the position of the negative charge, what is the magnitude of the electric field due to the three...

A point charge generates electric field lines that are radially directed from the source in spherical symmetry. Similarly, a line of charge generates electric field lines that are radially directed from the line of charge in cylindrical symmetry. Is there any way that a time-varying magnetic...

Hey friends, I am stuck up in the derivation of the electric potential energy due to a charge 'Q' at the origin on test charge 'q' at a point p (position vector 'rp'). The derivation is shown below, am just struggling with a minus sign... Electric Potential Energy at P = Work done to move...

Homework Statement A point charge q is a distance a > R from the axis of an infinite solenoid (radius R, n turns per unit length, current I). Find the linear momentum and the angular momentum in the fields. (Put q on the x axis, with the solenoid along z; treat the solenoid as a nonconductor...

Homework Statement Location A is 3.04m to the right of a point charge q. Location B lies on the same line and is 3.87m to the right of the charge. The potential difference between the two locations is VB - VA = 45.0V . What is the magnitude and sign of the charge? Homework Equations...

Homework Statement A right solid conducting cylinder has a total charge of +5.10 mC. Inside the cylinder a charge q = -1.55 mC rests at the center of a hollow sphere as shown in the diagram below. What is the charge on the surface of the hollow sphere? Homework Equations The Attempt at a...

Homework Statement Ok i got the hard parts, a and b. For some reason I'm stuck on part c, the direction of the electric field. Consider point a which is 70 cm north of a -4.2 µC point charge, and point b which is 76 cm west of the charge...

Homework Statement You measure an electric field E at a distance x from a point charge. What is the electric flux through a sphere whose center is at that distance and whose radius is less than x from the charge? Homework Equations E*dA = (q_enc)/(e_0) The Attempt at a Solution I'm...

Homework Statement a)A charge Q=10nC is placed at the origin, which is the centre of a cube with side lengths a=1cm whose faces are perpendicular to the x,y and z axis. What is the total flux through the box and what is the average of the perpendicular component of the electric field on the...

Homework Statement Three charges, q1 = +2.10 10-9 C, q2 = -3.09 10-9 C, and q3 = +1.08 10-9 C, are located on the x-axis at x1 = 0, x2 = 10.0 cm and x3 = 20.0 cm. Find the resultant force on q3. I am unsure of how to even attempt this problem...

Homework Statement A point charge +Q is surrounded by a spherical shell of inner radius a and outer radius b. The spherical shell has charge density \alphar. a) What is the electric field for r < a? b) What is the electric field for a < r < b? c) What is the electric field for r > b? d)...

What? W = \frac{\epsilon_{0}}{2} \int E^2 d \tau = \frac{\epsilon_{0}}{2 \left( 4 \pi \epsilon_{0} \right)^{2}} \int \frac{q^{2}}{r^{4}} r^{2} sin \theta dr d \theta d \phi = \frac{q^{2}}{8 \pi \epsilon_{0}} \int_{0}^{\infty} \frac{1}{r^{2}} dr = \infty Griffith explains this infinite energy...

Homework Statement What is the force on the 1.0nC charge in the middle of the figure due to the four other charges? http://filesmelt.com/dl/question.JPG Homework Equations F = K*q1*q2 / r^2 K = 8.99x10^9 The Attempt at a Solution Initial observation: The symmetry of the...

Homework Statement See figure attached for problem statement. Homework Equations The Attempt at a Solution I think my main source of confusion is this problem is how the force is acting on the electron. The picture shows that the electric field is pointing straight up...

Homework Statement A uniform electric field of magnitude 8.5×105 N/C points in the positive x direction. Find the change in electric potential energy of a 8.0 \muC charge as it moves from the origin to the point (6.0 m , 0). Homework Equations 1 N/C = 1 V/m \DeltaU = q\DeltaV E =...

A point charge accelerating through space generates an electric field and radiates energy. But how is this influenced if the point charge is moving along the field lines of an external electric field? Specifically how is calculation of radiated energy effected? Would you add the external field...

Homework Statement A negative point charge of 10 ^(−6 )C is situated in air at the origin of a rectangular coordinate system. A second negative point charge of 10^(-4) C is situated on the positive x-axis at a distance of 50 cm from the origin. What is the force on the second charge...

Homework Statement I am trying to find the force acting on a charge placed a distance r0 from the center of a spherical cavity of radius a. The entire cavity is immersed in a dielectric material, epsilon2. Homework Equations The Attempt at a Solution Here's my quandary: I can find the...

2 questions: 1. A point charge of 1.84 microC is at the center of a cubical Gaussian surface 55cm on edge. Find \Phi_E through the surface. So here I was thinking, well the shape doesn't matter so the surface can be a sphere, so I calculated it for a sphere and it was correct (taking the...

Homework Statement A point charge Q is at the boundary plane of two infinite, homogeneous dielectrics with dielectric constants \epsilon_1 and \epsilon_2. Calculate the electric potential, the electric field and the displacement vector at any point in space. Homework Equations...

Electric field of an infinite line charge and a point charge! Homework Statement An infinite line charge with linear charge density \lambda=2.0\muC/m lies along the y-axis. A point charge of 8.0 \muC is locate at (x,y)=(-1.0m, 2.0m). Find (a) the electric field at (x,y)=(1.0m, 2.0m) (b) Find...

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...

Point charge 2.0 uC is located at X= 0, X= 0.30m , point charge -2.0uC is located at X= 0 Y= -0.30m . What are (a)the magnitude and (b)direction of the total electric force that these charges exert on a third point charge Q= 5.0 uC at X= 0.40 , Y= 0? I drew a diagram of what was...

Two point charges are placed on the x-axis as follows: one positive charge, Q1= 3.96nC , is located to the right of the origin at x = 0.195m , and a second positive charge, Q2= 5.05nC , is located to the left of the origin at x = -0.295m . What is the total force (magnitude and direction)...

Homework Statement You have point charge a distance "d" above infinite conducting plane held at V = 0. What is the potential when you remove charge to infinity? Homework Equations The Attempt at a Solution I think I incorrectly used Coulomb's law between the charge (+q...

I'm curious. Say you have a solid, positively charged sphere with a uniform charge distribution. Now suppose you place a single, negatively charged electron inside the solid sphere. How will the electron behave? I assume the electrostatic forces exerted on the electron will ultimately tend it...

Homework Statement if a point charge is brought near a narrow stream of water will the water be attracted to the charge, repelled from it, or neither? why? water molecules are permanent electric dipoles. Homework Equations not sure The Attempt at a Solution i don't think the water...

Homework Statement Two point charges Q1 = 69.5 μC and Q2 = 19.9 μC are fixed on the two ends of the diameter of a semi-circle with a radius of r = 21.3 cm as shown in the figure...

I'm interested if it's possible to compute potential inside and outside dielectric sphere (with permittivity \varepsilon_1 ) which is placed in field of point charge q lying outside the sphere where permittivity is \varepsilon_2 . I've tried to solve it using Legendre polynomilas but I...

Homework Statement Point charge q1= -5.00 is at the origin and point charge q2= +3.00 is on the -x axis at x= 3.00 cm. Point P is on the y-axis at y= 4.00 cm . Calculate the electric fields E1 and E2 at point P due to the charges q1 and q2. Express your results in terms of unit vectors...

Point charge +Q is placed close to a very large conducting plane. A professor of physics asserted that the field caused by this configuration is the same as would be obtained by removing the plane and placing a point charge -Q of equal magnitude in the mirror-image position behind the initial...

Homework Statement I need help seeing if I did this right... This is from Fundamentals of Physics, 8th edition, volume 2. By Jearl Walker. Chapter 24, problem 88. A particle of positive charge Q is fixed at point P. A second particle of mass m and negative charge -q moves at a constant...

Homework Statement A point charge, Q, is located @ (0,0,d) above infinite conducting plane that lies in xy plane and is maintained at ground potential. Find: a.) surface charge density as a function of x and y on conducting plane, and b.) total charge induced on conducting plane...

If there is a point charge at the center of a hollow sphere that has voltage of V0. How would I go by solving the voltage and electric field distribution? I know I can use Poisson (Laplace) to find distribution had there been no charge inside the sphere, and could use Gauss had there been no V...

Homework Statement 2 particles of charge q and -2q are located as shown in http://s966.photobucket.com/albums/ae146/acherentia/ . A third charge Q is placed on the x-axis and it is found that the total electric force on Q is zero. In which region of the figure is Q located? Homework...

Given: a point charge (at rest at the Origin at time t=0) with a constant acceleration in the +x direction. Computation of E{x} at points on the y-axis produces negative values that approach negative infinity as y approaches zero. Extrapolation to y=0 suggests an infinite self-force on the...