What is Charge: Definition and 1000 Discussions

If an electron starts from rest 85.0 cm from a negative fixed source charge of -0.135 micro coulombs we use the equation ke final - ke intial + pe final - pe intial. In solving you use ke = pe which appears to cancel out the inital kinetic and potential energy but how can the initial potential...

Homework Statement Consider a conducting sphere with radius ##R## connected to a voltage source of ##V_0## volts. If the sphere is then covered by a dielectric spherical layer of radius ##9R## calculated the relative permitivitty ##\varepsilon_0## needed so that the field in the empty zone...

Please refer to the image attached. So, my doubt is: While calculating dW in the derivation, we know this work is being done by external force, because only then the unit positive charge can be made to move towards the charge +Q. So dW should be equal to Fext.dx but here in the book it is shown...

Quick question for you experienced "older people" :wink: (sorry, I couldn't word it in any better way - I think of it as a compliment of sorts in terms of acquired wisdom over me!): i.) What I mean is, can two doctor's of the same specialization (pick any...say, dermatology) charged wildly...

Homework Statement Two infinitely large conducting plates with excess charge 2Q and 3Q are placed parallel to one another, and at a small distance from one another. How are the charges 2Q and 3Q distributed? You may assume that infinitely large sheets of charge produce electric fields that are...

Homework Statement Distance between plates of a parallel-plate vacuum capacitor is d. The capacitor is attached to a battery that keeps it at a voltage V. The space between plates is now filled dielectric relative permittivity epsilon. How will charge density of the plates change? Homework...

Homework Statement Charged sphere with a mass of 15 mg and charge 2 nC moves with a speed of 15 cm/s towards a fixed point charge of 3 nC. How close will sphere approach charge? Homework Equations K=(1/2)*mv2 U=k*(Q1Q2/r) The Attempt at a Solution So I am not sure I approached correctly but...

Homework Statement Homework Equations E = σ / 2ε E = Fel / Q The Attempt at a Solution E = σ / 2ε = 17.7*10-9 /(2*8.85*10-12) E =1000 N/C ΣF = 0 Fel + mg = 0 Fel = - mg 1000 * q = - 10-3 q = - 10-3 / 1000 = 10-6 C = -1μC Could somebody check my answer please ?

We have the electric charge for the electromagnetic force, the color charge for the strong force. What is the charge for the weak force? Thank you. :)

Homework Statement A capacitor with initial charge q0 is discharged through a resistor. What multiple of the time constant τ gives the time the capacitor takes to lose (a) the first 1/8-th of its charge (b) 7/8-th of its charge? Homework EquationsThe Attempt at a Solution since ı know...

Can I put a resistor and control discharge of BCAP0050 2.7V 50F in order to charge 18650 battery?

Homework Statement A charge of +2 Q (A)is placed at the origin of a coordinate system and a charge of - Q (B) is placed at a distance d from the origin. How far from the origin must have 3rd charge +Q (C) be placed so that the net force on it is zero Newtons. Homework Equations Fe=kQq/r^2...

My textbook states: "The magnitude of charge of the electron or proton is a natural unit of charge." and then has an explanation that follows. It states, "...The charge on any macroscopic body is always either zero or an integer multiple (negative or positive) of the electron charge." Here is...

As we draw the electric field lines due to 2 equal magnitude and same nature charges. But when we solve the question concerning the same case we take the resultant of forces due to both charges at a test charge in such a manner that the 2nd charge(let I put the test charge on the left side i.e...

Hello, I am unsure whether this is in the right place, I do think this is nuclear physics however, I was hoping I could get some idea of whether I am answering this question correctly as unfortunately I won't be able to attend the class that explaining this concept. 34eV of energy, are lost...

Homework Statement [/B] Using Gauss law, Since there has been no mention of which type of charge density we have to find out I assumed it to be surface charge density since Gauss Law is in surface intergration , and I don't think there is any need to doing integration since the options given...

Homework Statement Homework Equations I am to use korchkoffs method to solve this problemThe Attempt at a Solution I already solved for the overall current which is the same throughout because C1 and C2 impeded current flow in sections of the circuit and i have found the charge on c1 BUT I...

As I understand it Cosmic rays are mostly protons which have a positive charge. If the overall charge state of the Earth remans neutral is there a similar outflow of positive charge or a source of incoming negative charge? Google wasn't very helpful.

Homework Statement A) Determine the net force on charge 1. B) What is the net electric field acting on charge 1? Homework Equations Fnet Enet The Attempt at a Solution Let North and East be positive. Because of symmetry, F21 = F31 F2 = F3 F2 = (9.0x109)(2.0x10-5(3.0x10-5) / (2.0m)2 F2...

In the wikipedia article about Charge, it says that when the symmetry group is a Lie group, then the charge operators correspond to the simple roots of the root system of the Lie algebra. So for U(1) group, how do the simple roots show that the charge in question is the electric charge?

Homework Statement Homework EquationsThe Attempt at a Solution When a sphere of charge Q is touched to A and removed , A acquires charge Q/2 . When B is earthed , potential of B becomes zero . B acquires some charge q . V( B's center ) = 0 kQ/[2(d+2a)] + kq/a = 0 q = -aQ/[2(d+2a)] Now...

Homework Statement Homework Equations Gauss's Law The Attempt at a Solution I simply used logic and observed the symmetry of the cube. If the charge is placed on the middle of the cube, the flux would simply be Q/∈0. The face of the cube itself can be split into 4 squares, with the charge at...

There's something I need to confirm about Gauss' law. If I have to determine the electric field at point P due to charge +q, I take a Gaussian sphere enclosing the charge with the point on the surface of the sphere. So Gauss law doesn't care about the charge +Q because the flux do to this charge...

Homework Statement Examine the charge distribution shown. b) What is the net electric field acting on charge 1? Homework Equations I used the equation E= (kq1/r^2) + (kq2/r^2) The Attempt at a Solution I subbed 9.0 x 10^9 in for k, 3.0 x 10^-5 for both q1 and q2, and 2m for r. My final answer...

There is a big sphere with charges distributed on the surface. N charges are distributed on a patch of the sphere (all the information of the charges such as their locations are known). Suppose the rest of the sphere has similar charge distribution as the patch, how to approximately calculate...

Homework Statement Homework Equations The Attempt at a Solution Here's my work :

Specifically, if I had a sphere or cylinder that accelerated upward or downward, it's clear that the distribution of charge, rho, would shift. However would the density turn into some function of increasing rho as the radius increases? I assumed that the density of charge would basically turn...

Homework Statement Homework EquationsThe Attempt at a Solution I will name the top left capacitor A , bottom left capacitor B and right capacitor C . Before the switch is closed , charges on A and B will be 20 μC each and that on C will be 40 μC . After the switch is closed ,both A and B...

Homework Statement Homework EquationsThe Attempt at a Solution Apologies for the question image not being very clear . I will refer capacitors by numerical value of their capacitance . The 6 , 4 , 8 capacitors are in parallel . 9 , 9 , 7 are shorted out .So , we can remove them from the...

I have been trying to understand some of the basic differences in the fundamental nature of leptons and quarks. One article on this issue compares leptons and quarks as "oranges vs apples" to which I basically agree except for one aspect. How can the charges of the quarks be 1/3 or 2/3 the...

I understand the basics of how capacitors work. If you hook one up to a power source, negative charge will build up on one plate, and positive charge will build up on the other plate. As the charges build up, an electric field forms between the plates and a potential difference is established...

So here is how my book defined electric potential. If you take a charge, it will have a corresponding electric field associated with it. If you put another charge in that electric field, an electrostatic force will act on it and give it kinetic energy. This kinetic energy can't come from thin...

Hi everyone, there's something that I can't comprehend: when a homogeneous is in a conservative and non-uniform in module electric field polarization expression is given by P=ε0χE. Supposing the most general situation there's: divP=ρp where ρp is the polarization charge density in the...

Hey guys, could anyone tell me if set up this integral correctly? Thanks in advanced!

Homework Statement Charge -q placed in front of an infinite plane of charge density σ To show the oscillatory motion of the charge -q It is allowed to impinge through charged plane Homework Equations Electric field in front of a charged plane is σ/2ε0 The Attempt at a Solution Force...

Homework Statement What is the relationship of charge polarity and voltage polarity? I understand an anion has negative charge and cation ion has negative charge, but does an anion have a positive voltage and the cation have a negative voltage? Given the above is generally true, when is the...

In classical field theories, I believe I understood how to derive a Noether charge that corresponds to a symmetry of action. And there is no problem in understanding its time independence. But in quantum field theory, it looks like the two different approaches, 1) Canonical quantization...

Many discussions cite CP transformation as the exchange of particles for anitparticles. But other places it says that charge conjugation alone is sufficient to turn a particle into its antiparticle. So, the question is, when you exchange particles for anitparticles, is it a CP transformation or...

So I understand that a capacitor consists of 2 plates separated by a distance which creates a potential difference between the plates. But I was confused, when watching this physics video it seemed to be saying that once the capacitor was fully charged, the plate closest to the positive terminal...

Homework Statement Describe the magnetic field you would observe if two coils were connected with magnetic fields pointing in opposite directions. Homework Equations No equation The Attempt at a Solution If the magnetic field was pointing in opposite directions, would it mean that it would...

Homework Statement [/B] For a straight wire of length 2L carrying a uniform charge density ##\lambda##, find 1) potential a distance z above the centre 2) electric field E at that point, 3) energy of this charge distribution Homework EquationsThe Attempt at a Solution 1) and 2) I can do...

Homework Statement A positive charge of magnitude Q1 = 8.5 nC is located at the origin. A negative charge Q2 = -8.5 nC is located on the positive x-axis at x = 16.5 cm from the origin. The point P is located y = 7.5 cm above charge Q2. Calculate the x-component of the electric field at point P...

Homework Statement (Problem 2.38 From Griffth's Electrodynamics): A metal sphere of radius R, carrying charge q, is surrounded by a thick concentric metal shell (inner radius a, outer radius b). The shell carries no net charge. Find the surface charge density ##\sigma## at R, a, and b...

Homework Statement Two batteries are connected to two identical capacitors X and Y.Initially all the plates of the capacitors are uncharged.How to find charge on each Capacitor in the given diagram.Let the Capacitance of Capacitor be C. Homework Equations 1.Q=CV 2.Kirchoff's law 3.C=C1+C2 (...

If given a capacitor with stored charge, would its charge remain constant before and after it is immersed in a liquid (i.e. distilled water)? Why? I know that before immersion, the capacitance would be = (ɛAV/d), but would that be the same if immerged in distilled water?

Homework Statement A sphere of radius R carries charge Q. The distribution of the charge inside the sphere, however, is not homogeneous, but decreasing with the distance r from the center, so that ρ(r) = k/r. 1. Find k for given R and Q. 2. Using Gauss’s Law (differential or integral form)...

Homework Statement A hollow conducting sphere has inner radius R and outer radius 1.5R. A +40nC point charge is placed at the center. What is the total charge on the interior and exterior walls of the sphere? R=10cm Homework Equations Gauss's Law σ = Qenc/A The Attempt at a Solution I'm not...

Homework Statement Find the distribution of charge giving rise to an electric field whose potential is $$\Phi (x,y) = 2~tan^{-1}(\frac{1+x}{y}) + 2~tan^{-1}(\frac{1-x}{y})$$where x and y are Cartesian coordinates. Such a distribution is called a two-dimensional one since it does not depend on...

Homework Statement The problem states: "A point charge q is located at a fixed point P on the internal angle bisector of a 120 degree dihedral angle between two grounded conducting planes. Find the electric potential along the bisector." Homework Equations ΔV = 0 with Dirichlet boundary...

This Science magazine news article describes a nano-scale arm made of DNA whose postion is controlled by charge. There is a little movie too.