Electric potential Definition and 1000 Threads

Homework Statement [/B] https://postimg.org/image/6dbwajk91/ (Image inserted by moderator to make it visible in-post) In the circuit the switch is closed for several seconds, then opened. Make a graph with the abscissa time in milliseconds, showing the potential of point A with respect to...

Homework Statement There is a solid cylinder of radius a and then empty space then a shell cylinder of radius b. Show that half of the stored potential energy lies within a cylinder of radius $$\sqrt{ab}$$ Homework Equations In the attempt The Attempt at a Solution I'm not sure what they...

Homework Statement In ##1+1##-dimensional spacetime, two objects, each with charge ##Q##, are fixed and separated by a distance ##d##. (a) A light object of mass ##m## and charge ##-q## is attached to one of the massive objects via a spring of spring constant ##k##. Quantise the motion of the...

Homework Statement Initial, 3 charges q are separated r at vertices of the equilateral triangle. Then they move freely to infinity. Find the velocity of charge when they are in infinity. Homework Equations If we seem 1 charge is affected by potential of 2 charges, we have...

For line integrals in vector calculus, \int^a_b F \cdot dl I almost always see the path oriented from a to b. But my textbook has the following (look at the first equation for V(r): Since the integral's limits are from O to r, I would have expected dl to also be pointing in the direction...

I am stuck with this problem: The right triangle shown with vertex P at the origin has base b, altitude a, and uniform density of surface charge σ. Determine the potential at the vertex P. First find the contribution of the vertical strip of width dx at x. Show that the potential at P can be...

Homework Statement In the figure, a metal sphere with charge q=https://edugen.wileyplus.com/edugen/shared/assignment/test/session.quest2561214entrance1_N10031.mml?size=14&ver=1471825532267&algorithm=1&rnd=1471825539091 μC and radius...

Homework Statement http://imgur.com/UsKsaOn Homework Equations Why is the answer in joules multiplied by 2/3 and 1/2? I can follow the rest of the problem. The Attempt at a Solution [/B] I get the same solution as my teacher if I use the constants 2/3 and 1/2. I just don't understand where...

I get easily confused when asked questions about electric field. One question that is bothering me is... Is it possible to have 0 electric field at a point, but at the same point have electric potential? I've read that the answer is yes, there can be a potential without a electric field, but...

Homework Statement Two equal isolated metallic bodies A & B start with no charge and zero potential. A is given a charge giving B the potential U. B is then Grounded giving A the potential U. What potential did A have before B was grounded? Hint: Use symmetry and use potential coefficients...

Homework Statement The electric field and the electric potential at a point are E and V respectively. (a) If E=0, V must be 0 (b) If V=0, E must be 0 (c) If E≠0, V cannot be 0 (d) If V≠0, E cannot be 0 Homework Equations [/B] E = V/d The Attempt at a Solution [/B] I basically substituted...

Formula for Electrostatic Potential due to a point charge is V=1/4π∈ Q1 Q2/r This implies that at r=0 value of the potential should be infinity. Is it True. If that is the case then how we say the terminals of a battery having positive and negative charge are having definite value of...

Homework Statement During a thunder storm, movement of water molecules within clouds creates friction which causes the bottom of the clouds to become negatively charged. This means that the bottom of the cloud and the ground begin to act like parallel plates. Once the electric field between the...

If I would displace a negative one-coulomb charge r meters from a positive charge, Q, the negative charge would gain electric potential energy that would be calculated by summing up all the values of the electric potentials along the line of its displacement, r. (I don't know calculus, but I...

Question states 'Determine the distance from the +4.0nC charge to the point, along the straight line between the charges, where the electric potential is zero.' This is as far as I've got: so I've used V=Q/4pi(epsilon0)r and then set it so V1+V2=0 (to find the point where the resultant...

Please could someone explain to me the graph on the left (for the positive source charge). I understand that the value for electric potential will be positive because of the source charge being positive, but why does it appear to decrease to zero at infinity, when the graph on the left (for the...

Homework Statement How do you calculate the electric potential at the midpoint between two point charges? Homework EquationsThe Attempt at a Solution I was asked to find the electric potential at the midpoint of every side of an equilateral triangle. I have no clue how I could do this find the...

Homework Statement Homework Equations E = kq/r2 V = -∫ E ⋅ ds W = -Vq The Attempt at a Solution a) I just summed up the electric fields: +ek/a2 +ek/a2 -ek/a2 so I get +ek/a2 as a result. Not sure if this is correct since -e has a y component so I was thinking to use sin but not sure which...

Homework Statement A metallic hollow cylinder has a diameter of ##4.2 cm##. Along his axis there is a wire having a diameter of ##2.68 \mu m##(considering it as a hollow cylinder). Between the cylinder and the wire there is a voltage of ##855 V##. What is the electric field on the wire surface...

Homework Statement Metal Surface is illuminated with 200nm wavelength light. Work Function of this metal is 3.0eV and its electric potential is 5V lower than a point of infinity. Determine max K.E of photoelectrons, which are just emitted from the work surface. Homework Equations K.Emax= hf...

Homework Statement The density of the charge inside of the sphere is given- ro=a*r+b/r The electric potential on the outer layer of the sphere is phi=0 The radius of the sphere is 58.4m r-is the distance from the center of the sphere What is the electric potential when r=15.4m? Homework...

Homework Statement Given two two grounded concentric spherical shells with radii a,b (a<b) and a point charge q between them at a<r=R<b find: 1.The surface charge density of the point charge using the delta function, assume the charge is on the z axis 2.By using the separation of variables...

For the diagram below, is it wrong? They have calculated the work done from i to f, using the force that is cross sectional to the particle. Shouldn't the force in the direction of the path be the the force x cos theta. They have summed the force that is not in the direction of the path?

Homework Statement The electric potential a distance r from a point charge q is 195 V, and the magnitude of the electric field is 2870 N/C. Find the values of q and r.Homework Equations 2780q=F Fr=W W/q=195 The Attempt at a Solution Using substitution I got r=.00679 meters, which is correct. I...

Homework Statement Two particles each with a charge of +3.00 μC are located on the x axis, with one particle at x = -0.80 m, and the other particle at x = +0.80 m. a) Determine the electric potential on the y-axis at the point y = 0.60 m.b) What is the change in electric potential energy...

Homework Statement Homework Equations The voltage between any two points due to the field from a point charge q is: Kirchoff's voltage laws, which states that the total voltage around a closed loop must be zero, i.e.: The Attempt at a Solution To find V(e<-d) I used Kirchoff's...

In the example my textbook has, the electric potential is calculating by integrating the electric field from infinity to R, radius of sphere, and then integrating the electric field from R to r, radius of point inside sphere. What I don't understand is why is the field integrated from infinity...

Homework Statement ≈ What is a 3D representation of voltage using Kq/r assuming a positive point charge and what is the equation in cartesian and cylindrical form2. Relavent equations Kq/r 3. Attempt at solution[/B] I was trying to get a better understanding of Voltage, to really FEEL...

Homework Statement A proton is in a place where the electric potential is V, and as a result it has a potential energy E. If you replace the proton with an alpha particle (twice the charge of the proton and four times the mass) in the same place, it will experience an electric potential...

Homework Statement A wire carrying a charge density of λ=.1c/m is bent into a circle of radius r = 5 cm. What is the electric potential at the center of the circle Homework EquationsThe Attempt at a Solution λ/2Ԑ0 is this right? i do not really understand it or where my radius went

There's this problem that was given in my physics class.. "Three identical, negatively charged particles are situated at rest in a straight line, as shown below. All three are released simultaneously, and are free to move. Find the maximum velocities attained by particles A, B, and C. They have...

I am confused about the signs in calculating the potential energy change from the electrostatic force. Suppose there was a point charge +q1 and I moved a second point charge +q2 from a distance of b from q1 to a distance of c from q1. c is smaller than b. So the potential energy change is - ∫...

Homework Statement You start at a distance r from a point charge. The electric potential is 4500V at that point, and the electric field is 2.3x105N/C. a) What is r? b) What is the electric potential and magnitude of the electric field at a distance of r/4?Homework Equations v= kq/r E=kq/r^2...

I was studying for (first year) physics class and was playing around with the Bohr Model of Hydrogen. I tried calculating the electric potential at the Bohr radius r =5.29e-11 m, where V = \frac{e}{4 \pi \epsilon_0 r} (from the point-charge formula for electric potential) and I got 27.19 J/C...

Homework Statement A plastic circular washer is cut in half and has a charge Q spread uniformly over it. If the electrical potential at infinity is taken to be zero, what is the electric potential at the point P, the center of the old washer? The inner radius of the washer is a, the outer...

I learn that we can expand the electric potential in an infinite series of rho and cos(n*phi) when solving the Laplace equation in polar coordinates. The problem I want to consider is the expansion for the potential due to a 2D line dipole (two infinitely-long line charge separated by a small...

Homework Statement https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xfp1/v/t1.0-9/12417589_10205411987170709_6390638921146727371_n.jpg?oh=e166de7d1246b4afacebe60bac5ce654&oe=570B03E4&__gda__=1460454017_6cad38b2934b81eeeccbeedf05704e4b Homework Equations Electric potential The Attempt at a...

I'm solving a problem numerically where I have some charge density above an infinite, grounded conducting plane and want to determine the electrical potential at a given point. My intuition says that this is not simply given by the potential of the charge density above the plane, since this will...

Homework Statement My textbook states that for point charges ##q_1, q_2, ... ,## where distance between ##q_i## and ##q_j## is ##r_{ij},## the total potential energy U is the sum ## U = \dfrac{1}{4\pi\epsilon_0} \sum_{i<j} \dfrac{q_iq_j}{r_{ij}} ## and specifically mentions not to count them...

Homework Statement Three equal charges are equidistant from point Z. What is the electric potential at point Z? Homework Equations V = kq/r The Attempt at a Solution Because the charges are equal and equidistant from point Z, would I find the electric potential by: V = (3kq)/r ? Thank you!

Homework Statement The figures showing the potential variation inside a PN junction normally shows the potential to be constant in the neutral P and N regions Homework Equations V=Q/4ΠΣr The Attempt at a Solution Since the potential due to the positive and negative charges should also exist...

Problem: When a dielectric slab is inserted between the plates of one of the two identical capacitors in Fig. 25-23, do the following properties of that capacitor increase, decrease, or remain the same: (a) capacitance, (b) charge, (c) potential difference (d) How about the same properties of...

We recently started to learn about electricity in school and I'm trying to understand the concept of voltage(potential differance). From what i understand, electrons flow from the negative terminal to the positive. The electrons at the negative terminal will have 1.5 J of potential energy per...

So I have two questions relating to potential difference 1.An electron with a velocity of 5.0x10^6 m/s injected into a parallel plate apparatus through a hole in the positive plate. it moves across the vacuum between the plates, colliding with negative plate at 1.0x10^6 m/s. what is the...

In the example in the picture, we can see that they chose the limits of integration to be from 0 to R_0. Why didn't they choose x (that is, from 0 to x)? Isn't that what we normally integrate over when we find potential energy and electric fields? Thank you

Homework Statement 1. We are considering a step junction at equilibrium(no external voltage applied). 2. The potential variation is shown as negative potential at P region(which is shown as constant) and increasing through the transient region to become positive in the n region. Homework...

Homework Statement A charge of q1=-9.8 nC is uniformly distributed around a thin plastic ring lying in a yz plane with the ring center at the origin. A q2= -8.0 pC point charge is located on the x axis at x = 3.4 m. For a ring radius of 1.2 m, how much work must an external force do on the...

Homework Statement A sphere of radius R carries an electric charge Q, uniformly distributed inside its volume. (a) Using the expression for the electric field given in the lectures, compute the electrostatic potential V (r) inside and outside the sphere. Homework Equations E[/B] = -∇V The...

Homework Statement An alpha particle is a nucleus of helium. It has twice the charge and four times the mass of the proton. When they were very far away from each other, but headed toward directly each other, a proton and an alpha particle each had an initial speed of 3.6×10−3c, where c is the...

Homework Statement A small ball has a mass of mass m 4.0 x 10^-8 kg and a charge of q = -2.0 x 10^-5 C. It enters a box with an initial speed of v0 = 1.0 x 10^4 m/s. The point where the charge leaves the box is at a voltage 350 kV higher than the entry point. Homework Equations...