Potential difference Definition and 688 Threads

Homework Statement three point charges are located on a circular arc as shown: a) find the electric potential at the centre of the arc (point P) b) find the electric potential energy of a 25 pC point charge placed at P Diagram: [ r= 4 cm = 0.04 m]...

I reduced to equivalence capacitance and found the potential difference between the nodes based on what was provided using the rules of parallel and series and my final answer doesn't match the answer given. I have a test in two days and have been studying this along with other subjects. Could...

I have an exam on monday, for a course I'm not familiar with. I have studied the material and tried some example exam question but I can't seem to figure out how to get to the result of the following questions. Q1: Homework Statement A sample of hydrogel is in equilibrium with a sodium chloride...

Homework Statement Find the potential difference between points a and b. Picture of Circuit involved. Homework Equations V=IR ΔV=Vb-Va The Attempt at a Solution Pretty much completely lost, due to the only one current shown I'm not sure which way the current flows through...

Homework Statement A circuit consists of a series combination of 5.50-kΩ and 4.50-kΩ resistors connected across a 50.0 V battery having negligible internal resistance. You want to measure the true potential difference (that is, the potential difference without the meter present) across the...

Homework Statement A 2kg charge of +3C moves through a potential difference of 6V and begins at rest. What is its final velocity? Homework Equations m = 2kg q = +3C dV = 6V Vi = 0 m/s Vf = ? F = m*a (Vf)2 = (Vi)2 + 2(a)(d) dV = (ke)(q)/(r) 1 N/C is equal to 1 V/m The Attempt at a...

Hi, I'm trying to understand electrical potential and potential difference. I was wondering if anyone can confirm if what I have written is correct or not? If not I would be glad to learn what I am yet not understanding. When you push away an electron of negative charge from a positive...

Homework Statement A spherical capacitor contains a charge of 3.10nC when connected to a potential difference of 220V . If its plates are separated by vacuum and the inner radius of the outer shell is 5.00cm . Part A) Calculate the capacitance. Homework Equations C = Q/V C = Aε0/d...

Homework Statement Please don't do the problem for me, but explain to me in detail each steps I should take and why in my calculations (so I didn't include any numbers). There's an insulating infinite cylinder of equal charge distribution at origin (density given- rho). Let's say it's radius...

Homework Statement Charge 6.00 is distributed uniformly over the volume of an insulating sphere that has radius = 5.00 . What is the potential difference between the center of the sphere and the surface of the sphere? Homework Equations ΔVab= -∫E*dl Electric field inside an insulating...

Homework Statement A proton has an initial speed of 3.5×10^5 . What potential difference is required to reduce the initial speed of the proton by a factor of 2? Homework Equations KE=.5*m*v^2 EPE=q*V The Attempt at a Solution I did KE=.5(1.67x10^-27)(3.5x10^5/2)^2 and then divided...

Calculate the potential difference that would have to be maintained across the plates of a parallel plate apparatus, if the plates were 1.2cm spat, to create an elecric field strength of 1.5x10^4 N/C. i have no idea how to do this! someone please help

Homework Statement What is the potential difference between points a and b in the diagram? http://imgur.com/Ubr4A Homework Equations The Attempt at a Solution I have calculated the currents to be: I1=0.30A I2=0.65A I3=0.35A What I tried doing was (0.30*5) - 0.35= 1.15 V but...

****WARNING-THIS IS NOT A HOMEWORK-WARNING**** Hello dear Physics Forums users, I have no idea about how to find the potential difference between two points in a complex circuit. I m not even sure if I really know how to find it in a basic circuit. Please help me and enlighten me with your...

I understand the definition to be the amount of work done in moving a charge from one point to another divided by the charge. If you have a standard 1.5 volt battery, the charge should move easily from one end of the circuit to the other because the positive terminal attracts the electrons...

The potential difference between two large parallel plates is varied as V=at; a is a positive constant and t is time. An electron starts from rest at t=0 from the plate which is at lower potential. If the distance between the plates is L, mass of electron m and charge on electron -e then find...

Sorry for this post, but I am desperate for an answer. Please reply thanks in advance Consider a simple circuit composed of a battery whose ends are connected by a wire. The potential difference of the battery is Vbatt ohm's law gives: V=IR If the resistance of the circuit is ignored then the...

why is potential difference same in parallel and gets divided in series,also what does it means this much pd is apllied by cell.pleaseeeeeee explain working of all this,i am getting frustrated as i am not able to understand

Homework Statement The Cells in a circuit has 2V and 4V emfs and 2Ω and 6Ω internal resistance respectively. Find the potential difference between AB Homework Equations V=IR Kirchoff's Laws The Attempt at a Solution The attempts are in image

Can anyone tell me the relationship between work done and potential difference?? CAN ANYONE TELL ME THE RELATIONSHIP BETWEEN WORK DONE AND POTENTIAL DIFFERENCE?? If more work is being done across a component(for ex due to increased resistance), does the pd across it increase or decrease? I...

Homework Statement A thin plastic spherical shell of radius a is rubbed all over with wool and gains a charge of -Q. What is the potential relative to infinity at location B, a distance a/3 from the centre of the sphere?Homework Equations \text{$\Delta $V}=\int...

hello... potential difference between two points in a circuit is the work done by the electric field to get a charge from point to another and for the emf it's also the work done but my question is for a potential difference the work is negative( the electrons lose energy) and for the emf the...

I really need to know the difference between the two as I have an exam tomorrow D:. What is the difference between the two and how do I calculate each one of them? The book says " IR is the potential difference that is measured across the load resistor R. This is the same as the potential...

See attachment. Assume that the two capacitor's plates were originally connected together as one capacitor, and thus their plate separations were equal, along with their charge densities. In the photo below then, the capacitor has been split down the middle and with one halve the distance...

I need help with the attached exercise. Problem is not that I am not able to do it. You can find the field of an infinite cylinder with Gauss' law and then use that to find the potential difference. My solutions notes however do it in a slightly different way, still arriving at the correct...

Homework Statement Find the charge find the charge: mass : 3.6*10^-12 kg electric potential difference: 250.4 V parallel plates are 0.41 cm apart PLEASE DO NOT link me a wikipedia page.. or give me a one sentance explanation of something unrelated to this question Just need to know how to...

Homework Statement What is the current and potential difference across the 4Ω, 12Ω, and 8Ω resistors. What is the potential difference across a and b https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/389632_3598331272733_1107039398_3285590_155442550_n.jpg Homework Equations V=IR...

Homework Statement Circuit is at this link: http://www.colorado.edu/physics/phys1120/phys1120_sp08/hws/capa8_figs/gian1946.gif 1. What is the potential at point a with S open (let V=0 at the negative terminal of the source, and assume it's a long time after the circuit was connected to the...

Homework Statement Four capacitors are connected as shown in the figure below. (Let C = 18.0 µF.) Find the equivalent capacitance between points a and b Calculate the charge on each capacitor, taking ΔVab = 17.0 V Homework Equations Q = CΔV C = Q / ΔVΔV1 = ΔV2 = ΔVtot (for parallel...

How is electric potential manipulated in batteries? Why do some batteries have a rating of 1.5v and others have ratings of 1.25v? I'm not looking for the answer of "its the materials used in the chemical reaction" because I know that.WHAT DO THESE MATERIALS DO DIFFERENTLY TO THE PHYSICS OF THE...

Homework Statement Through what potential difference must an electron be accelerate, starting from rest, to acquire a speed of 0.99c? vf=0.99c(m/s), vi=0(m/s), m=9.11e-31(kg), q=1.6e-19(C) Homework Equations E=γmc^2=V*q The Attempt at a Solution I plugged in all knowns in the equation and...

Homework Statement A resistor made from a shell with an inner radius r1 and an outer radius r2 hasa conductivity sigma. The current flows radially outward. 1.What direction does the E field point in. 2. Is the potential difference V2-V1 positive or negative. Homework Equations None...

Homework Statement The electric third rail in a subway system is made of steel, measures h=0.1m high, w=0.02m wide, and carries a current I=110A. Calculate the Hall potential difference across the rail from corner to opposite corner due to the Earth's magnetic field with components...

I'm having trouble trying to understand what a volt is, and I thought this question might be able to help me understand, so.. For example: If there are 10^6 electrons in one place, and 100 electrons in a different place, what will the potential difference between these two places be. Also...

A bird, whose feet are 3cm apart, perches on a bare "High tension" power line carrying a current of 720A. If the wire has a resistance of 80μΩ/m, calculate the potential difference between the bird's feet. Do you think the bird will be electrocuted? r = p * (L/A) I have the...

Homework Statement Ions with mass m and charge q are accelerated through a potential difference V. They then enter a uniform magnetic field perpendicular to their velocity and are deflected in a semicircular path of radius R What potential difference V is needed so that singly ionized 12C...

Homework Statement Two capacitors are identical, except that one is empty and the other is filled with a dielectric (k=3.6). The empty capacitor is connected to a -11V battery. What must be the potential difference across the plates of the capacitor filled with a dielectric so that it stores...

1. Homework Statement [/b] Problem - Compute the potential difference between the points (4,6,3) and (8,1,6) due to a constant electrostatic field given by E = (2 ihat + 7 jhat + 12 khat) N/C. distance in metersHomework Equations Fq = qE Vr = Keq1/(r-r1) Fq = (Kq1 (r-r1))/(r-r1)3 The...

Homework Statement An electron is accelerated from rest through a potential difference of 26000 V, which exists between plates P1 and P2, shown below. The electron then passes through a small opening into a magnetic field of uniform field strength, B. As indicated, the magnetic field is...

I'm having a problem with this although I just finished the chapter about electric potential and potential energy in University physics by young and freedman and I need to understand this because the next chapter is about capacitors and dielectrics and there is an example just like this...

Homework Statement A sphere with radius 2.0 mm carries a 1.0 μC charge. What is the potential difference, VB - VA, between point B 4.0 m from the center of the sphere and point A 9.0 m from the center of the sphere? (The value of k is 9.0 × 10^9 N∙m2/C2.) Homework Equations The formula...

Homework Statement The capacitors in the figure are initially uncharged and are connected, as in the diagram, with switch S open. The applied potential difference is V_ab = 210V. a) What is the potential difference V_cd? b) What is the potential difference across each capacitor...

I'm a little bothered with the inconsistency in notation of electric potential (V) and potential difference (ΔV) because they're apparently used synonymously... but what really confuses me more is that I've seen absolute value around ΔV sometimes. It may not matter (theoretically or...

Homework Statement An electron is accelerated by a potential difference of 3000V and enters a region of a uniform magnetic field. As a result the electron bends along a path with a radius of curvature of 26.0 cm. Find the speed of the electron as it enters the magnetic field. Homework...

i know that the p.d measured across XY is the p.d. across resistor B in this picture: http://img812.imageshack.us/img812/7665/68689848.png But what if resistor B is removed like in this picture: http://img707.imageshack.us/img707/7798/41743055.png What is the p.d across XY now? Is it 0...

This is why I think this is the case, I can't come up with any other reason and have been researching all over the place. I do have a knowledge of circuits, I'm doing an electronic engineering course, but the reasoning has never been explained, as if it's unnecessary to understand why, but I am...

Homework Statement Given is the X-ray machine in which electrons are accelerated in the potential difference of 10000 V before hitting the electrode and loosing its energy. Find the maximum energy of the emitted X rays in keV and in Joules. Homework Equations The Attempt at a...

For conventional current, they say that it moves from high potential to low potential. What does this mean? pd at a point is the potential at the further end minus the closer end. So what does it mean? Thanks for the help!

Homework Statement The electric field in a region is given by E=2x^2 i +3y j where the units are in V/m. What is the potential difference from the origin to (x, y) = (2, 2) m? Homework Equations E = -gradient of V The Attempt at a Solution - derivative of the x-component: 2/3...

Hello! Okay so I understand that electric potential: V = kQ/r ...must be influenced by the radius doubling because it would make the potential energy half of what it originally was because of the proportionality law, v is proportional to 1/r. With electric fields though, how can...