Electric potential Definition and 1000 Threads

Homework Statement I'm getting really confused when it comes to electric potential. The definition I am using is 'the work done per unit charge on a small positive test charge when it is moved from infinity away to a point'. My first problem is that I'm not sure whether 'the work done' refers...

Hi guys I just want to make sure that my understanding of potential difference is right or wrong I just want someone to tell me whether my understanding is right or wrong. I know that when we move a charge if it's attracted to another charge it gain potential energy and when we leave it it lose...

Hi! I'm having an hard time with a trivial question that suddenly I can't figure out: Computing the potential between the plates of a spherical capacitor. The problem is taken from this url (first page and a half)...

Homework Statement Imagine a lithium atom where the two electrons in the first orbital are at exact opposite sides of the nucleus and the electron in the second orbital is in line with the other electrons so that the three electrons and the nucleus all lie on a straight line. How much work...

Homework Statement If I have a electric source charge, does that mean that electric potential increases as r increases (because it gets increasingly less negative as you go farther from the source charge) as opposed to a positive charge in which potential energy would increase as r...

Homework Statement The formula for Electric Potential as I have it is: "Let Q be a point source charge. At any point P that's a distance r from Q, we say that the electric potential at P is the scalar given by this formula: electric potential = k * (Q/r) My question is what if at...

Homework Statement Which one of the following statements concerning electrostatic situations is false? a) No work is required to move a charge along an equipotential surface. b) If the electric potential with a region of space is zero volts, the electric field within that region must also be...

I was working on a problem out of Griffiths, and have become a bit confused. The problem is regarding to Earnshaw's theorem, which states that a particle cannot be held in stable equilibrium by electrostatic forces. (3.2 for anyone with the text). He suggests a cube with a positive charge on...

What is the potential of Earth with respect to (wrt) infinity (C=710uF)? I am assuming that infinity is the correct reference here. Suppose a capacitor that's normally used in an electric/electronic circuit is a) discharged by connecting its two (2) terminals. b) then they are...

Homework Statement Rank the electric potential energy at point ##P## for the following four cases: http://gyazo.com/c7d9df3d3d64cda909ddc0d2ab7686bc Homework Equations ##\Delta U_e = - W_∞## The Attempt at a Solution I believe it should be ##U_2 > U_1 > U_3 > U_4##, but I am not certain.

[SIZE="4"]Definition/Summary Voltage is electric potential difference, which is potential energy difference per charge: V\ =\ U/q Energy per charge equals energy per time divided by charge per time, which is power divided by current (watts per amp): V\ =\ U/q\ =\ P/I Since potential...

Homework Statement My questions reads: An electron is pulled away from a fixed charge of 1.3μC. The electron is moved from the positive charge to 4.0 cm away from the charge. If the electron is released from the 4.0 c mark, what is the max velocity of the electron? Homework...

I am attempting to work through a paper that involves some slightly unfamiliar vector calculus, as well as many omitted steps. It begins with the potential energy due to an electric field, familiarly expressed as: U_{el} = \frac{\epsilon_r\epsilon_0}{2} \iiint_VE^2dV =...

Homework Statement A solid conducting sphere having a charge Q is surrounded by an uncharged concentric conducting hollow spherical shell. Let the potential difference between the surface of the solid sphere and that of the outer surface of the hollow shell be V. If the shell is now given a...

I have just solved a problem about electric potential and it is: " A positive point charge of 1.0 nC is located at position x=0.00 . A second point charge q=-1.0 nC is located at x=0.10 m. (a) What is the value of the electric potential on the x-axis at x=0.3 m ? (b) What is the value of the...

Please I want to check my answers of this problem:- Two charges 4 µc , -6 µc are placed on the x-axis 10 cm apart. where is the electric potential be zero ? My Answer is:- "4 cm apart from the charge of 4 µc" Is that right ?!

Electric potential energy of a charge q at a point in an electric field due to any charge configuration as the work done by the external force in bringing the charge q from infinity to that point without any acceleration.. In this definition, why charge is moved without any acceleration?

There are two charges 2 C and 3 C and 100 cm apart from each other. Find a point where electric potential is zero? Consider 2 C charge on the origin.I have tried out but don't get it solution... 1) If you take point between two charges then 2 C----------100 cm------------------3 C...

There are two sphere of radius a and b and they are connected by conducting wire. Then why the electric potential becomes same of both the sphere?

If a positive charge A moves towards another stationary positive charge B then the A's electric potential energy increases. But shouldn't the electric potential energy of B also increase as it is also in a way moving towards the A inside the A's electric field? So shouldn't the total...

Hello, my questions are not really about an exercise or something "given". Instead, I'm having trouble understanding the concepts behind electric potential and work formulae/meaning. Maybe (probably) I missed the basics. Assume that I'm working with a puntiform charge. 1 - I've seen...

Homework Statement Three positive charges lie on the x-axis; q1 = 15 μC is at the origin, q2 = -30 μC is at x = 2 m, and q3 = 15 μC is a x = 3 m. ( please also refer to the attachment.) Find the electric potential and electric field at point “P” aroused from q1, q2 and q3. The Attempt at...

Hello! For Single Charge: I studied the formula for electric potential for a point charge (V=kq/r). It was derived when the test charge approached the source charge from infinity "head-on". In this case the electric field due to source charge and displacement of test charge were vectors in...

Homework Statement Consider a membrane which is permeable to a singly charged ionic species. If the concentration on one side is 25 times that of the other, what is the electric potential required to maintain a net flux of zero at 37C? Homework Equations I'm not sure: U = KQq/r flux...

In a velocity selector apparatus, i had an electric potential set across two points, and a proton at rest at one end. The potential was 350 V. My instructor used : qV = 1/2 mv^2 to find the velocity at the end of the apparatus. Where did the left hand side of the eqn come from??

Homework Statement 1. Consider a line of charge (with λ charge per unit length which extends along the x-axis from x=-∞ to x=0 (a) Find all components of the electric field vector at any point along the positive x-axis (b) Find the electric potential difference between any point on the...

Homework Statement A conducting spherical shell has inner radius a, outer radius b, and has a +Q point charge at the center. A charge of -Q is put on the conductor. a) What is the charge on the inner and outer surface of the shell? b) What is the electric field everywhere? c) What...

As the title says, what is the electric potential of a metal cylinder? If I am missing any variables, which variables do I need? My little brother asked me this but I don't want to turn up short-handed. I'm not really a physics guy

When a positive charge leaves the positive part if the battery it has maximum electric potential energy then as it moves through a wire with a zero resistance the charge is closer to the negative side of the battery. So, while traveling in a wire in a circuit does it lose electric potential...

Homework Statement Two charges of equal magnitude Q are held a distance d apart. Consider only points on the line passing through both charges. If the two charges have the same sign, find the location of all points (if there are any) at which the potential (relative to infinity) is zero. a)...

This isn't a homework question, but while working on some questions in Physics AP C, I've come across several questions involving 0 PD (potential difference). My question is simple; what does 0 PD mean? so far i know that 0 potential difference of any kind is arbitrary, since it represents the...

I'm having a hard time understanding why the electric potential halfway between two equal but opposite charges is 0. If I put a positive charge halfway between a 5 mC charge and a -5 mC charge, it will accelerate toward the negative charge, but how can it do this if it starts with no potential...

Homework Statement hi, all, can anyone explain why the ans is C for this question? http://i.imgur.com/yGyu5G3.jpg for the second question? shoudnt the ans is D ? http://i.imgur.com/R4Gvjoz.jpg Homework Equations The Attempt at a Solution

1. Explain why the electron moves in the above way (from left to right between two parallel plates that is positively charged on the left, negatively charged on the right) in terms of electric potential energy Homework Equations 3. I know the electron moves from left to right when...

Homework Statement Which one of the following statements best explains why it is possible to define an electrostatic potential in a region of space that contains an electrostatic field? A) Work must be done to bring two positive charges closer together. B) Like charges repel one another...

Homework Statement So the problem revolves around a Linear Electric Quadrupole, with two positive charges on z-axis (in positions s and -s from origo) and two negative charges in origo. 1. Show that potential from a position R can be written as 2. The quadrupole moment can be...

Hey, folks. I've typed out the question here. I hope you don't mind my just linking this (if that's against the rules or something, I'll type it out). I'm still pretty confused about what to do. I assume, as usual, it's probably something... well... stupid—but I can't figure out what. Thanks...

Are these the same thing? Or does the electrical potential difference refer to the voltage source only?

Homework Statement When is electric potential negative and when is it positive? Homework Equations V=Es The Attempt at a Solution I first thought that when you are moving in the same direction as the electric field the electric potential will be a positive value. However I...

For when there is a negative test charge: The work done to get from infinity to r would be negative, corresponding to a decrease in potential energy so since dr must be a path element and therefore in the negative direction (towards the source of the E field) does that mean the...

Homework Statement A flat ring of inner radius R1 and outer radius R2 carries a uniform surface charge density σ. Determine the electric potential at points along the axis (the x axis). [Hint: Try substituting variables.] Homework Equations V = (kQ)/r The Attempt at a Solution...

Hello I'm very confused on what the difference is between electric potential and Potential Energy. I though they were the same but I realized they're not after I got a 30% on a physics quiz. I tried googling it but it keeps telling me that potential energy is equal to mgh which is from...

Homework Statement Two point charges are placed on the x axis. The charge + 5 q is at x =1.50m , and the charge −q is at x= -1.50m . There is a point on the x-axis between the two charges where the electric potential is zero. Where is this point? The electric potential also vanishes...

I'm trying to understand why the voltage across parallel circuit elements is the same. I keep finding the answer "because they are both connected to the same voltage source." Why is it the case, in a physical sense, that voltage MUST be the same across, say, capacitors that are connected in...

is electric field strength always equal to negative potential gradient or can it be equal to positive potential gradient sometimes?

Homework Statement A conducting metal ball of radius 2m with a charge of 3μC is surrounded by a concentric spherical shell of inner radius 4m and outer radius of 5m with a total charge of 4μC. Determine the electric potential in volts between the ball and shell at a radius of 3m...

I am having some troubles wrapping my head around the electric potential concept. From what I gather it is a separation of charge? Is this true? On a more formal level electric potential energy is the amount of energy in joules it takes to move a charge against an electric field or the amount...

Homework Statement The ring is in the z,y plane. D = 2m R = 4m Q = 8 * 10^-6 C X = distance to the edge λ = dQ/dX dX = rdθ dQ = infinitely small charge dX = infinitely small arc of ring What is the potential difference at the point D perpendicular to the centre of the ring? Homework Equations...

This is essentially the problem. And this is what I did. Realizing the following: E = -▽V I simply took the derivative in regards to the vertical component, in this case "a". So: -dV/da [the above formulae] And I got the following: Κλl/(a sqrt(l^2+a^2)) Does that seem about right...

My book says it is zero, but I don't know where to start , why is it zero ? I have to take an exam in few hours :cry: so a simple explanation would be appreciated ( I'm not studying pure physics:smile: Here are the electric fields of the three regions . Thanks in advance :smile: