Potential difference Definition and 701 Threads

  1. L

    Potential Difference: Negative Potential Explained

    Homework Statement Like I'm doing a problem right now which is too long to copy or paste here, its basically a circuit where there are 3 batteries in parallel, and in one of them, current is passing through the battery from the positive to the negative terminal (from high to low potential)..now...
  2. A

    How Do You Calculate the Potential Difference Between Two Points in a Circuit?

    Homework Statement For the circuit in the figure below, V = 3.56 V and R = 2.04 Ω. Find the potential difference between points a and b. This is the link to the figure: http://i749.photobucket.com/albums/xx137/abcdmichelle/physics/26-62alt1.gif Homework Equations V=IR The Attempt...
  3. I

    Potential difference on a conical surface

    hi i am posting a problem 2.26 from griffiths EM book third edition.i am also attaching the solution from the book's solution manual. in the solution, griffiths has taken the ring as the differential element. but i want to know if we can take the small rectangular patch on the conical surface...
  4. I

    Potential difference on a conical surface

    hi i am posting a problem 2.26 from griffiths EM book third edition.i am also attaching the solution from the book's solution manual. in the solution, griffiths has taken the ring as the differential element. but i want to know if we can take the small rectangular patch on the conical surface...
  5. Z

    Potential Difference: 1 J = ? V

    Homework Statement if 1.0 joule of work is required to move 1.0 coulomb of charge between two point in an eletric field the potential difference between the two point is 1) 1 .0 x 10 exponenet 0 v 2) 9.0 x 10 exponenet 9 v 3) 6.3 x 10 exponenet 18 v 4) 1.6 x 10 expeonent -19 v...
  6. K

    Potential Difference in Series and Parallel circuit

    Ok I'm new here. I'm only a seconday student, recently exposed to Physics. I have a few doubts and questions on the chapter Electricity. Why is the potential difference same for all the bulbs in a parallel circuit? My teacher only seems to explain this by rewriting some equations, but what I...
  7. C

    Emf V & Potential Difference in a Resistor

    Homework Statement Thermal energy is to be generated in a 0.31 resistor at the rate of 11 W by connecting the resistor to a battery whose emf is 2.1 V. (a) What potential difference must exist across the resistor? (b) What must be the internal resistance of the battery...
  8. C

    Capacitors: charge, potential difference and stored energy

    Homework Statement The 50Volts is going through 3 capacitors. C1 = 4.0 µF, C2 = 8.0 µF, and C3 = 9.0 µF, The URL below is the image of how the capacitors are connected: http://www.webassign.net/hrw/26_27.gif For each capacitor i need to find the charge, the potential difference and the...
  9. I

    Potential Difference and Resistors

    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...
  10. I

    Current due to Potential Difference

    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...
  11. A

    Calculating Intensity of Light from Potential Difference

    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...
  12. L

    Potential difference in circuits

    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...
  13. M

    How Can a Wire Carrying Current Be an Equipotential Surface?

    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?
  14. M

    Wires and potential difference

    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?
  15. L

    Why Isn't Terminal Potential Difference Equal to EMF When I=0?

    Homework Statement I'm just wondering for a terminal potential difference in a battery, I know the formula is V= E-Ir where E=electromotive force and r is the internal resistance. But in my textbook, it says that when I=0, that doesn't mean that V is the same thing as E...it says 'the...
  16. R

    Potential difference required to stop a particle

    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...
  17. S

    Potential Difference and Power Dissipation 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)...
  18. L

    Potential difference of a battery

    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...
  19. F

    How Batteries Create Potential Difference Between Terminals

    how do battries create potential diffrence between their terminals?
  20. L

    Potential difference in uniform electric field

    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...
  21. S

    Charge on a glass bead derived from potential difference between 2 points

    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...
  22. C

    Electrical potential difference

    Homework Statement A grey rectangle is a uniform resistive but conducting coating on a substrate. This means that electrons can flow through it, but only slowly, and hence their paths follow the field lines. Attached, and in electrical contact with this, are two silvered metallic conductors...
  23. A

    Millikan oil drop experiment potential difference

    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...
  24. C

    Current, direction of flow and potential difference in a circuit

    Homework Statement The question is 'Calculate the current in each of the three resistors in the circuit in Figure 4 and indicate the direction of current flow. What is the potential difference between A and B?' Homework Equations Kirchhoff's first and second laws, Ohm's law The...
  25. E

    Potential difference in a circuit

    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...
  26. P

    1 Volt and potential difference?

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

    What Is the Potential Difference When Moving a Coulomb Between Plates?

    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...
  28. R

    Potential difference, electric potential energy and work

    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...
  29. R

    The potential difference in a capacitor with dielectric

    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...
  30. C

    How to determine the 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.
  31. C

    Potential Difference between Concentric Circles

    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...
  32. H

    Potential difference of a group of atoms

    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)...
  33. X

    Confused: potential difference vs. voltage drop?

    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...
  34. C

    Minimum Electrical Potential Difference required to stop Alpha particle

    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...
  35. I

    Finding potential difference between two points on a cone

    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...
  36. S

    RC and RL(frequency and potential difference)

    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...
  37. J

    Potential Difference and Electric Potential

    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...
  38. S

    What is the minimum potential difference?

    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...
  39. M

    Finding Current and Potential Difference in a LCR Circuit

    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...
  40. T

    Current in a resistor and potential difference

    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...
  41. S

    Find the maximum potential difference that can be applied to a capacitor

    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)...
  42. T

    Potential Difference of C2: 9V Capacitors in Series

    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...
  43. C

    Calculating Potential Difference on A Capacitor, RC Circuits

    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...
  44. K

    Cahnge in potential difference of moving electron

    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...
  45. K

    Electric Potential and 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...
  46. F

    Electrical potential difference given velocity

    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...
  47. D

    How Do You Calculate the Potential Difference in a Charged Spherical Insulator?

    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...
  48. E

    Potential Difference in a varying field

    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?
  49. A

    Potential Difference across Capacitor.

    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...
  50. I

    Kinetic Energy of Ion accelerated across potential difference

    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)?
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