Potential difference Definition and 688 Threads

Homework Statement Suppose the three resistors in the circuit have the values R1 = 180, R2 = 220, and R3 = 350, and that the emf of the battery is 18.0 V http://session.masteringphysics.com/problemAsset/1126258/3/5416321031_128.jpg Find the potential difference across each resistor...

Homework Statement Consider a rectangular block of metal of height A, width B, and length C , as shown in the figure. If a potential difference V is maintained between the two A X B faces of the block, a current Iab is observed to flow. Find the current that flows if the same potential...

Homework Statement It's a problem I'm having with my experiment. We set up a diode LASER through 2 polarizers, and changed one of the polarizers' angle with respect to the other, to demonstrate Malus's Law. We used some sort of photo detection device (which we were told uses the...

Homework Statement In series and parallel circuits, I'm confused like let's say 2 resistors are placed both in series and parallel, how can we tell when the potential difference is at a maximum? Like if one of these resistors has a higher value than the other, do we use that in our calculation...

Recently in physics I've learned that equipotential surfaces are always conductors in electrostatic equilibrium.. so no moving charges. I'm a little confused, then, of how a wire carrying current is considered an equipotential? If charges are moving how can the potential be constant?

Recently in physics I've learned that equipotential surfaces are always conductors in electrostatic equilibrium.. so no moving charges. I'm a little confused, then, of how a wire carrying current is considered an equipotential? If charges are moving how can the potential be constant?

Homework Statement A particle with a charge-to-mass ratio of 50 C/kg is moving at a speed of 200 m/s. What electric potential difference is required to stop the particle? Homework Equations F = Eq? The Attempt at a Solution I am completely uncertain how to start this problem...

A potential difference V is applied to a wire of cross-section area of 1 unit, length 1 unit, and conductivity σ. You want to change the applied potential difference and draw out the wire so the power dissipated is increased by a factor of 30 and the current is increased by a factor of 4 . a)...

1. What is the potential difference DeltaVab between points a and b when the switch is open? Closed? 2. DeltaV = IR 3. I solved I for the battery, which is 8A. What do I use for my R value to solve for DeltaV between a and b, though? I tried, for example, DeltaV = IR = 8A*6ohms = 48V. I guess...

how do battries create potential diffrence between their terminals?

Homework Statement A uniform electric field of magnitude 325 V/m is directed in the negative y direction. The coordinates of point A are (-0.200, -0.300) m and those of point B are (0.400, 0.500) m. Calculate the potential difference V(B)-V(A). Homework Equations The Attempt at a...

Homework Statement A 2.0 mm diameter glass bead is positively charged. The potential difference between a point 2.0 mm from the bead and a point 4.0 mm from the bead is 500V. What is the charge on the bead? Actual Answer 4.2*10^-10 I am unable to understand or even get near this...

Homework Statement in a Millikan oil drop experiment, a uniform electric filed of 1.92 x 10^5 N/C is maintained in a region between two plates separated by 1.5 cm. Find the potential difference between the plates. Homework Equations mg = q x E The Attempt at a Solution in order to...

Homework Statement What exactly happens to the voltage... in between things such as resistors, and bulbs? It isn't a homework question it is just something that is bothering me. Homework Equations V=IR for resistors Sum of V in a closed loop is zero. The Attempt at a...

How far do you need to separate two opposite 1C charges inorder for the potential difference to be 1v?

Homework Statement Well honestly I am not that great in physics. I thought someone can help me with this question about potential difference. If a 120J of work are performed to move one coulomb from a positive plate to a negative plate, what potential difference exists between the plates...

Four charges are arranged at the corners of a rectangle as shown in the diagram. How much work needs to be done to move the charge q2 to infinity? Since change in PEe = W, am I suppose to find total potential electric energy of the four charges and then subtract the total potential electric...

Homework Statement Two identical capacitors are connected in parallel, charged by a battery ov Voltage V, and then isolated from the battery. One of the capacitors is then filled with a material of relative permittivety E. Homework Equations What is the final potential difference...

1. A horizontal rod(oriented in e-w direction) is moved northward at constant velocity through a magnetic field that points straight down. 2. Why is the west end of the rod is at higher potential than the east end? 3. I have no idea how to obtain any information about V.

Homework Statement Three concentric circles of radii 1.5m, 2.5m, and 4m are filled with a gas that breaks down in electric fields greater than 1.6 x 10^7 volt/meters. What is the highest potential difference that can be maintained between the innermost circle and the outermost circle. (Hint...

I encountered a question in my book: a)An electron is trapped in a solid between a group of atoms where the potential is +2.8V The de Broglie wavelength of this electron is 1.2nm. Calculate i) its speed ii) its kinetic energy iii) the sum of its kinetic energy and its potential energy b)i)...

Homework Statement In Fig. 28-5a calculate the potential difference across R2, assuming = 14 V, R1 = 6.0 , R2 = 3.0 , and R3 = 2.0. (image isn't working online, but it's a simple circuit- all the resistors are in series) Homework Equations V = IR The Attempt at a Solution Req...

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 x 10-25 kg, and moves away from the location of the decay with a speed of 2.62 x 105 m/s. Determine the minimum electric potential...

Hello I am solving some problems from "Intro to EM" by David Griffiths ( third edition) Problem 2.26 ( attached file 2.26.jpg) and I have also attached the solution from the solution manual (griffiths-2.26.jpg). For both part a and b I am getting different answer. I have chosen vertex as...

Homework Statement 1.(RC in AC)What will happen to the potential difference on the capacitor as the frequency increases? In terms of the reactance of the capacitor, why might this happen? 2.(RL in AC) What will happen to the potential difference on the inductor as the frequency increases...

Homework Statement A uniform electric field of magnitude 375 N/C pointing in the positive x-direction acts on an electron, which is initially at rest. After the electron has moved 3.2 cm, what is a. the work done by the field on the electron b. change in potential energy associated with the...

What is the minimum potential difference applied to an x-ray tube if x-rays of wavelength 0.250 nm are produced? E=hf f=c/wavelength f=3e8/.250e-9 =1.2e18 then i applied it to the first equation using Plancks constant as h and my final answer came out to be 7.95e-16 KV...

Homework Statement There is a circuit, with the L and R in parallel and then there is a capacitor as well. There is a switch and a battery source. The E = 12 V and R is 1.37ohms. The switch is closed and the capacitor is uncharged and all currents are 0 Homework Equations That's what...

Homework Statement In the circuit of figure p28.23, determine the current in each resistor and the potential difference across the 200 ohms resistor. http://s848.photobucket.com/albums/ab41/tag16/?action=view&current=circuit.jpg&newest=1 Homework Equations 1/Req= 1/R1+1/R2+1/R3+1/R4...

Homework Statement Determine a) the capacitance and b) the maximum potential difference that can be applied to a Teflon-filled parallel-plate capacitor having a plate area of 1.75 cm^2 and plate separation of .04 mm. Homework Equations A=.0175 d=.04e-3 k=2.1 C=k(epsilon-not)(A/d)...

Homework Statement Two capacitors C1= 6 μF and C2 = 12 μF are connected in series, and the resulting combination is connected to a 9.00 V battery. What is the potential difference across C2? Homework Equations V=Q/C The Attempt at a Solution Q isn't given so I'm not sure what I'm...

The circuit of Figure P.72 has been turned on for a long time, so that you can ignore the transient behavior of the capacitor. Voltage of Battery V = 31 V (e) What is the potential difference across the capacitor C (C = 9 µF)? I thought about using Kirchoff Voltage Law, but I also though that...

Homework Statement As an electron moves through a region of space, its speed increases from 2.2e^6 m/s to 6.0e^6 m/s. The electric force is the only force acting on the electron. a) Did the electron move to a higher potential or a lower potential? b)Across what potential difference...

Homework Statement Calculate the speed of a proton that is accelerated from rest through a potential difference of 135 V. 1 km/s (b) Calculate the speed of an electron that is accelerated through the same potential difference. 2 Mm/s Homework Equations V=U/q The Attempt at a...

Homework Statement An electron moving parallel to the x-axis has in initial speed of 3.7x10^6m/s at the origin. Its speed is reduced to 1.4x10^5m/s at the point x=2.0 cm. What is the potential difference between the origin and this point? Which point is at the higher potential? Homework...

A solid insulating sphere has radius a = 3.2 meters and total charge Q = 3.6 Coulomb's. Calculate the potential difference between the center of the sphere and a point r = 0.64 meters from the center of the sphere. (A positive answer represents the center is at a lower potential, a negative...

Homework Statement Homework Equations V_f - V_i = - \int_i^f{\vec E \cdot d\vec s} The Attempt at a Solution Can I assume that the V_i is 0? V= - \int{\vec (4x) \cdot d\vec s} V= - \int{\vec (4x) \cdot d\vec s} V= -4x(s) V=-4x(2.51) V=-10.02x At this point, what is done?

Homework Statement Homework Equations Not sure which equations to use but I know that we'll have to use the answers from part a and b to answer the questions. The Attempt at a Solution What I did was that I said that C1 and the 6 microfarads are parallel to C2 and the 2...

An ion of 64Zn30+ with an initial kinetic energy of 9.88 keV is accelerated across a potential difference of 277 Volts. What is its kinetic energy after acceleration (in keV)?

[b]1. A 2.05 µF capacitor (#1) is charged to 901 V and a 6.68 µF capacitor (#2) is charged to 671 V. These capacitors are then disconnected from their batteries. Next the positive plates are connected to each other and the negative plates are connected to each other. What will be the potential...

A small sphere with mass 2.10 g hangs by a thread between two large parallel vertical plates 5.00 cm apart . The plates are insulating and have uniform surface charge densities + sigma and - sigma . The charge on the sphere is q = 7.70×10−6 C What potential difference between the plates will...

Moderation Note: Split from the original thread, which can be found https://www.physicsforums.com/showthread.php?p=680746#post680746" A uniform field does not have potential difference:smile:

Homework Statement What potential difference is needed to stop an electron having an initial speed of 4.2*10^5 m/s? Homework Equations W = delta K W = q*delta V The Attempt at a Solution So I'm pretty sure that the potential difference should be negative in order to stop the...

Homework Statement Electrons are accelerated from rest through a potential difference of 250000 V. What is the final speed predicted classically? What is the final speed predicted relativistically? Homework Equations KE=0.5mv^2 KE=mc^2-m0c^2 The Attempt at a Solution...

Electrons are accelerated from rest through a potential difference of 277000 . a) What is the final speed predicted classically? in m/s b) What is the final speed predicted relativistically? in m/s

Homework Statement A charge of -3.00 C is fixed in place. From a horizontal distance of 0.0450 m, a particle of mass 7.20x10^-3 kg and charge -8.00 C is fired with an initial speed of 65.0 m/s directly toward the fixed charge. How far does the particle travel before its speed is zero...

Homework Statement A bird stands on a DC electric transmission line carrying 2800A. The line has 2.5 x 10^-5 ohms resistance per meter, and the bird's feet are 4.0 cm apart. What is the potential difference between the bird's feet?Homework Equations I wish I knew The Attempt at a Solution...

Homework Statement Find the potential difference between two points located at distances R_1, and R_2 from a point source. Solution Potential difference = V_{p_1, p_2} = V_{abs_1} - V_{abs_2}. Question Hows is the solution above true? What if the angle formed between P_1, Q, P_2 increases...

I understand what voltage is in the context of electrostatics, but the definition of circuits seems foggy to me. The common definition I see is something like "voltage is the amount of work per unit charge to be done on a charge moving from A to B". However, this is usually in the context of...

Homework Statement An electric field is given by E_x = (5 kN/C) x^3. Find the potential difference between the points on the x-axis at x= 1 m and x = 5 m. Answer in units of kV.Homework Equations V = -EdThe Attempt at a Solution V1 = -5*10^6 N/C * 1 = -5*10^6 volts V2 = -5*10^6 * 5 = -25*10^6...