Charges Definition and 1000 Threads

Homework Statement Homework Equations The Attempt at a Solution I am not sure how to proceed with the given problem. I can write down the net force on any of the charges but what should be the condition that the chain breaks? :confused: Any help is appreciated. Thanks!

Homework Statement Three point charges are located in an equilateral triangle with side 0.330 cm, where q1 = +8.30 µC, q2 = −8.20 µC, and q3 = +1.90 nC. A) What is the electric field at the location of q3? Enter the x component, then the y component. B) What is the force on q3? Enter the x...

Dear All, I have some doubts in induced charges surface distribution.suppose their is a spherical shell and a negative charge is kept inside the shell(not at the center of shell) then induced charge distribution at inner surface of cavity is not uniform due to eccentric position of charge but...

Suppose we have two insulated uncharged metal spheres,say X and Y, in contact with each other.A negatively charged object C is brought near X My first question is:Do all of the electrons move to the sphere Y since electrons are free to move? Then if X is touched momentarily with a finger,and...

Homework Statement If a small positive and negative charge are created at rest at a point between electrodes as shown in the figure. In which direction will they move if one would neglect gravity? Ignore those weird arrows, those are for later questions. Homework Equations...

I'm a little confused about something that came up in a lecture a while back. There's nothing about it any books or online seemingly... The energy for bringing four point charges from infinity to a their relative positions was calculated. This was done by saying the work to bring in the first...

Hello, So I assume, ionization occurs, when an electron has enough energy to either overcome the potential (Coulomb) barrier, or tunnel right through it (or can the overcoming of the barrier even be described as a 100% chance of tunneling?). If an alpha particle interacts with an atom, it...

Homework Statement A point charge q2 = -4.5 μC is fixed at the origin of a co-ordinate system as shown. Another point charge q1 = 3.6 μC is is initially located at point P, a distance d1 = 7.3 cm from the origin along the x-axis 2) The charge q2 is now replaced by two charges q3 and q4...

Homework Statement Hi! Bear in mind, before shooting me down, that I'm very new to electrostatics and extremely (i.e. today) new to the method of image charges, and all my learning is dodgy book-learning and not learning from asking the learned questions. This said, I just want my...

Homework Statement The ball 1 can be charged to a certain charge Q by a generator. After that, through contact with the ball 2, the first ball can transfer to second ball part of its charge. After the first contact, the ball 2 has a charge q. Before the contact, the ball 2 was neutral. What...

Homework Statement Use a Cartesian system whose origin coincides with the midpoint between the two charges and write the expression for the magnitude of electric field \vec{E} on the line passing through the two charges. Then Show that when the two charges have the same sign, there is a...

Homework Statement Three capacitors of 2μF, 3μF and 5μF are independently charged with batteries of emf's 5V, 20V and 10V respectively. After disconnecting from voltage sources, these capacitors are connected as shown in figure with their positive polarity connected to A and negative polarity...

Homework Statement A positive point charge Q1 = 2.51×10-5C is fixed at the origin of a coordinate system. A second positive charge Q2 = 4.07×10-6C is fixed to the x-axis at x = +2.07m. Find the location of the place along the x axis, where the net-force on an arbirary test-charge (positive...

Does there exist a fool-proof way of doing it? I've scoured the forums, and I've already found this question, but the answers are not satisfying. Here for example is exactly my question: https://www.physicsforums.com/showthread.php?t=525291&highlight=polyatomic+ions I've already...

Homework Statement Two spheres have a charge of q a stationary sphere between them has a charge of -q. The 2 positive spheres move like conical pendulums at a constant velocity of 12.0m/s in uniform circular motion. What is the magnitude of charge q? Homework Equations Electric Force...

Voltage as the "cause of motion" of charges? I know voltage is defined as the potential energy difference per unit charge between two points A and B. In textbooks they often describe this potential difference as the "cause" of current through a wire. Further, if this potential difference gets...

Homework Statement Four charges, each q in magnitude, are arranged in a square, two positive and two negative, in opposite corners. The square is L length on each side, and the charges are all in the same plane as shown in the diagram. Show work and units for full credit. q+ -----B----- q- | |...

The surface photovoltage effect suggests that the potential at the surface of a semiconductor will change when it is illuminated since hole-electron pairs are created. The regions near the surface (depletion regions) contains defects that create a built-in voltage and built-in potential and...

Homework Statement A charge + q is fixed at each of the two points (±a,0,0). Show that the potential V at a point (x,y,z) near to the origin may be expressed as V = [q/4∏*ε*a] [[2+(2x2-y2-z2)/a2] where x, y and z are small compared with a. Homework Equations V(x) = q/4∏i*ε*r ...

These are 2 stand alone problems, however the answers disagree with one another and I am trying to reconcile their differences. Any insight would be appreciated! :) The answer is C. The answer provided with this question is that "there is no dependence on resistance of any kind". However the...

Hi, Is Newton's 3rd law applicable to electric charges? I have a problem with a situation where two identical positive charges moving perpendicular to each other. The magnetic forces exerted by each one on the other have same magnitude but their directions are not opposite.

Cathode rays are the flow of election, since electrons are -vely charged, is it normal for the rays to travel almost in a bundle without getting dispersed due to it's repulsion? If you say it's because of its velocity, then if you imagine each electrons, they are at almost rest to each other...

Hi there, Is it true that the magnetic field of a straight wire is the same when the charges are moving at low speeds (v <<c) as when they are moving at relativistic speeds (v~c). The extra relativistic factor the magnetic field gets from the moving charges cancels upon integrating. According...

explain me a simple reason why magnetic field is only caused when charges are moving and not when their is no current moving but that is quite tricky even because if we say that their is no potential difference between the wire but in that case also electrons are moving in a random path...

Homework Statement in the following figure, the dashed line denotes a Gaussian surface enclosing part of a distribution of four positive charges. a) which charges contribute to the electric field at P? b) is the value of the flux though the surface, calculated using only the...

Homework Statement What is the electric field magnitude midway between charges of Q1 = 1 C and Q2 = 11 C separated by 2 m? Homework Equations E= k (Q/r^2). The Attempt at a Solution 9E9 x 1C / 1^2 = 9E9 N/C 9E9 x 2C / 1^2= 1.8E10 N/C. What do I do from here? Any help...

my guess was Jefimenko's equations could be used, am i right? also are there any other relevant equations or methods? also what does the current density derivative in the equation (in terms of the acceleration) for the magnetic field physically mean? p.s. my first post on the internet!

Homework Statement The .274 and .88 was found using the equation of electrostatic force . Homework Equations K=q1q2/d^2 The Attempt at a Solution Would I just tan inverse of .274N and .88N which would be 17 degrees. However my question is: how to determine the reference pt: would...

Homework Statement Both Q1 = Q2 = +5E-6 and are harnessed to screen and in a vacuum.----Q1---A----Q2------B--------P this is x axis, A and B are distances Homework Equations kQ/r^2 The Attempt at a Solution So the E field at point P is KQ1/(A+B)^2 + KQ2/(B)^2 My question is Why...

Homework Statement Three charges are in a straight row. The first charge has a value of 5.00 x 10-5 C. The second charge also has a value of 5.00 x 10-5 C and is 2.50 cm to the right of the first charge. The third charge has a value of -2.50 x 10-5 C and is 2.00 cm to the right of the...

The two charges are (-q) and q. I'm just curious as to how you go about graphing them. Thanks!

Do moving charges 'create' or 'induce' magnetic field around them? I believe that induction is a phenomenon in which the behavior of one object depends on the behavior of another object provided they interact with each other. In this case, the moving charge is just surrounded by air or vacuum...

Homework Statement A certain coaxial cable consists of copper wire, radius a, surrounded by a concentric copper wire of outer radius b. The space between is filled with a dielectric with a relative permittivity of \epsilon_{r} = \frac{s}{a}, a \leq s \leq b Find the bound charges by using two...

I found in this forum an old thread regarding this topic, but as it didn't have (in my opinion) a satisfactory answer, I decided to open a new one. Usually when one begins to study Electromagnetism, Coulomb's law in introduced as an experimental result valid for static point charges. From...

Homework Statement Plates of a capacitor have charge 2CE and CE initially. Now the switch S is closed. Which of following statements is true? Assume that the battery, resistor and wires do not have any capacitance. A)There is no change in charge at outer surfaces of the capacitor. B)There...

Homework Statement Two isolated point charges, -7 μC and +2 μC, are at a fixed distance apart. At which point is it possible for the electric field strength to be zero? (A)......(B)...(C).....(D) o----------------------o----------o---------------o ......-7 μC...+2 μC...

Homework Statement Consider the circuit shown in the attachment. Capacitor C1 is first charged by closing switch S1. Switch S1 is then opened, and the charged capacitor is connected to the uncharged capacitor by closing S2. Calculate the initial charge acquired by C1 and the final charge on...

Homework Statement I am trying to write a program in MATLAB where I input certain values and get a result of possible x and y coordinates. Writing the program is not a problem, I just need to simplify the equation for matlab. I am trying to rewrite a formula so I can find what the distance is...

The concept of "space charge" around grain boundaries keeps coming up in my reading. I understand that charges tend to build up at grain boundaries, but I'm not sure why. Can someone explain what "draws" charges to boundaries?

Can you check this? -- Charges and Forces... Homework Statement A +3-mC charge and a -4-mC charge are fixed in position and separated by 5 meters. A)Where could a +7-mC charge be placed so that the net force on it is zero? B)Where could a -7-mC charge be placed so that the net force on it is...

Homework Statement Homework Equations E = kq1q2/r2 The Attempt at a Solution Please correct me if I am wrong but I think it is A. Since doubling the charge, doubles the potential as well, while doubling the radius between the charges would just exponentially decrease the...

Ok. I understand like repel and opposite attract. There are these physics homework with 3 charges and find the force from 2 of them on one. I understand the math: the only problem is my signs are wrong due to not understanding the direction of the force. For example, There's a positive...

1. A student is performing an experiment with two identical small metal balls, A and B. Initially, Ball A contains 6.0-uC net charge with unknown sign and Ball B is neutral. The student brings them in contact and then separated them by 20cm. Both of the balls are remained isolated. Is the...

Homework Statement three particles having charges 1:2:3 produce the same point on the photographic film in the thomson experiment. The masses are in the ratio of a) 1:2:3 b)3:2:1 c) 2:3:1 d) 1:3:2 Homework Equations a = F/m = Eq/m The Attempt at a Solution Since all the...

Homework Statement i'm having a bit of trouble understanding/visualising why the electric potential is zero in the red cross within region III and the green dot within region II from my current understanding, the green dot is where the potentials from both charges are equal and...

Homework Statement When the bound charges in a dielectric arrange themselves in an electric field, this is called: A) Bound Charge Alignment B) Dielectricity C) Polarization D) Reactance Homework Equations - The Attempt at a Solution I know that this is a straightforward...

Homework Statement Two point charges q1 = -6.15 nC, and q2 = -10.5 nC are separated by 25.0 cm (see figure below). (a) Find the net electric field these charges produce at point A (b) Find the net electric field these charges produce at point B (c) What would be the magnitude and...

Homework Statement Two points are resting on a string. The first point is resting at x = 6.0 m and has charge q1 =−7.1 µC. The second point is resting at x = −4.0 m and has charge q2 = −4.3 µC. At what location is the total electric field zero from the two points(other than infinity)...

Two point charges are placed on the x-axis as follows: charge q1 = 4.01nC is located at x= 0.201m , and charge q2 = 5.00nC is at x= -0.301m. What is the magnitude of the total force exerted by these two charges on a negative point charge q3 = -6.03nC that is placed at the origin? I know I...

Homework Statement Three point charges have equal magnitudes, two being positive and one negative. These charges are fixed to the corners of an equilateral triangle. The magnitude of each of the charges is 2.9 µC. The lengths of the sides of the triangle are .02m Calculate the magnitude...