Charged Definition and 1000 Threads

Homework Statement Two long wires with the same cross section are arranged in air PARALLEL to each other . Assume both have opposite charge densities +λ and -λ. The distance between the axis of the wire is η times larger than the radius(r) of wires cross section . What would be the capacitance...

Homework Statement The first part is to calculate the electric field everywhere in space given a body of 2 spheres of radius R and distance d apart (d<R), located on the z-axis, with charge density ρ and -ρ. Of course when r>>R this is essentially a dipole. The second part is to approximate the...

How an electron moves when it is released from rest to a positively charged hollow cylinder? The hollow cylinder is finite and insulating. The electron is constrained to move only in z direction (into the center of the hollow cylinder). My thinking is that there is no electric field inside the...

just above the surface it's (kq/r^2) where r is the radius of the sphere and just below the surface it's zero, so is the electric field zero also exactly on the surface ? (as the q enclosed then will be zero since the flux is coming from the surface and not actually penetrating it) and...

i know it s zero because of the electrostatic equilibrium, but in terms of point charges : from the charge distribution on the sphere surface if we consider 2 point charges opposite to each other in direction : it s logical that at the point in the mid distance between them the electric field...

Hey, I've been wondering about the behavior of flowing charged particles lately. In particular, imagine that I have a tank of charged fluid. Lets assume this charge density is 1 C/cm^3. I then allow the fluid to flow through a pipe of 1 cm^2 cross-sectional area at a rate of 1 m/s. Thus there...

Whenever a charged particle is in motion ,there is both electric and magnetic fields created. Why is it that we only study one of it at a time ?

In an example in my book, the author poses the following question: Given two large plates at a distance d from each other with arbitrary charges Q' and Q" (with Q' on the bottom plate and Q" on the top plate), how are the charges distributed on the plates? The author lists the following...

Homework Statement A hollow spherical conductor, carrying a net charge +Q = 47 pC, has inner radius r1 = 5.9 cm and outer radius r2 = 11.9 cm. At the center of the sphere is a point charge +Q/2. a. Find the potential at r = 18.0 cm. b. Find the potential at r = 10.0 cm. c. Find the potential...

Homework Statement A conducting sphere with radius R is charged to voltage V0 (relative to a point an infinite distance from the sphere where the potential is zero). What is the surface charge density σ? Express your answer in terms of the given quantities and ϵ0. Homework Equations Electric...

The time t taken by a capacitor of capacitance C in a charging circuit with a resistance R in series with it to accumulate charge q is given by the equationt=τln(q/(Q−q)),where τ is the time constant given by τ=RC and Q is the maximum charge the capacitor can have when fully charged in that...

Homework Statement If you have a ring of charge, is it valid to say lambda = Q/L, or is it lambda = dQ/dL? Homework EquationsThe Attempt at a Solution

Homework Statement An infinite solid cylinder of radius A and uniform charge distribution ρ is surrounded by a thin cylindrical envelope of radius B and linear charge distribution λ. The two cylinders are co-axial. Find the potential V(r) as a function of r from r=0 to r=∞. Homework Equations...

Homework Statement [/B] Charged particles with equal mass and identical initial velocities move through regions of space that may have magnetic fields. Rank the magnetic field in each case from greatest to least. For this question, fields out of the page will have positive values, while fields...

Homework Statement A flat ring (inner radius R_0, outer radius 4R_0) is uniformly charged. In terms of the total charge Q, determine the electric field on the axis at points a) 0.25R_0 b) 75R_0 from the center of the ring. [Hint: The ring can be replaced with two oppositely charged...

Hello and thanks for reading Homework Statement I'm in high school. I chose my yearly project in physics, and wanted to make a cloud chamber. The subject is "deflection of charged particles in a magnetic field", so I must set a magnet alongside the cloud chamber. I've prepared for it, bought...

Current moves from positive terminal to negative terminal. But electrons moves from the negative terminal to positive terminal due to its smaller mass . But why it is said that current moves from positive terminal to negative terminal ?

Why are charged objects attracted to neutral objects? If I'm correct, electrons and protons aren't attracted to neutrons.

In the charged rod experiment, why didn't my hand neutralize the charge formed in the rod, since my body is a conductor and it is connected to the Earth?

Homework Statement An alpha particle (helium nucleus, charge +2e) starts from rest and travels a distance of 2.5 cm under the influence of a uniform electric field of magnitude 12.5 kV/m. What is the final kinetic energy of the alpha particle? Homework Equations U = 1/2 QV = 1/2 C(V^2) =...

Homework Statement A positively charged particle initially at rest on the ground accelerates upward to 200m/s in 2.60s. The particle has a charge-to-mass ratio of 0.100 C/kg and the electric field in this region is constant and uniform. What are the magnitude and direction of the electric...

Homework Statement Text description: Let V(z) be the potential of a ring of charge on the axis of symmetry at distance z from the center. Obtain the first two non-vanishing terms of the multipole expansion for V(z) with z>>a where a is the radius of the ring. Can you see by symmetry that the...

I have been thinking about a simple thought experiment in classical electromagnetism that seems to disobey conservation of energy. I'd be very interested to hear where people think I'm going wrong. Imagine that we have two oppositely charged objects with charges +q, -q and masses m. Assume...

Homework Statement A point charge q1 = -6.1 μC is located at the center of a thick conducting shell of inner radius a = 2.8 cm and outer radius b = 4.8 cm, The conducting shell has a net charge of q2 = 2.6 μC. Homework Equations E = (kQ)/r2 F = (kq1q2)/r2 The Attempt at a Solution I honestly...

hello! what is the most efficient way to produce charged particles? like protons (H+) or electrons or ions or anything like that thanks!

Homework Statement An expanding sphere, radius ##R(t) = vt## (##t>0##, constant ##v##) carries a charge ##Q##, uniformly distributed over its volume. Evaluate the integral Q_{eff} = \int \rho(\vec{r},t_r) d\tau with respect to the center. (##t_r## is the retarded time and ##d\tau## is an...

“Plants are usually charged negatively and emit weak electric fields. On their side, bees acquire a positive charge as they fly through the air. No spark is produced as a charged bee approaches a charged flower, but a small electric force builds up that can potentially convey information. The...

How cathode is positively charged in voltaic cell?I mean at cathode reduction takes place ,but the electron which is gained for reduction comes from anode,than why cathode becomes positively charged ?As electrons are from anode not from cathode that means electrons are not lost by cathode ,so it...

Consider a Maximal (negatively) charged black hole. Can it have "flavor" or weak charge? Suppose a muon collided with that hole. Would an electron be emitted? What if electron neutrinos collided with that black hole; would electron neutrinos more likely be emitted as Hawking Radiation...

Homework Statement Two charged, parallel, flat conducting surfaces are spaced d = 1.3 cm apart and produce a potential difference ΔV = 625 V between them. An electron is projected from one surface directly toward the second. What is the initial speed of the electron if its comes to rest just at...

Homework Statement Calculate the electric field on axis of a disc that has charge +q on one half and -q on the other. Describe the behavior of the potential along the same axis at points far from the disc. Homework EquationsThe Attempt at a Solution My intuition says its zero, as for every...

Homework Statement One of two nonconducting spherical shells of radius a carries a charge Q uniformly distributed over its surface, the other a charge -Q, also uniformly distributed. The spheres are brought together until they touch. What does the electric field look like, both outside and...

Hello, I have to compare the real solution of the electric field radiated by a sphere, having 10 cm radius, charged with 1e-012 C (perfect conductor), something like E=f(x) where x is distance from the sphere, from 0m (surface of the sphere) to 1m, with numerical solution. I tried Ansoft...

Suppose we're given the action S=-mc\int ds + \frac{q}{c}\int A_{\mu}(x) dx^{\mu}-\frac{1}{4c}\int d^{D}xF_{\mu \nu}F^{\mu \nu} The first two integrals are over the particle's worldline while the last is over spacetime. So I'm able to successfully vary the action with respect to the gauge...

Homework Statement Two radioactive isotopes of singly charged plutonium(Pu-249 and Pu-244) are accelerated through a potential difference of 3.00kW and enter a uniform magnetic field of 1.50T directed perpendicular to their velocities. By performing relevat calculations, show that the ratio of...

This may be a silly question, but what prevents the decay of a Pion into a (anti) Tau and (anti)Tau neutrino. I can see the process for the electron but not for the tau.

Homework Statement After a capacitor of capacitance ##C_1## is charged up to a voltage ##V_o##, the Battery is removed from the circuit. Another capacitor of capacitance ##C_2## is connected in series with the capaciotr ##C_1##. Find the charge on each capacitor after equilibrium is attained...

Let's say there's a question where there are two charges placed, and a point in between and above the line connecting the two charges forms a triangle like this: http://session.masteringphysics.com/problemAsset/1413940/2/p19.5.jpg What would one have to do in order to find the electric field...

Homework Statement Particles of charge q and 3q are placed 90m away from each other. A third particle is place in between them and the total electric force on this particle is zero. Determine the position of this particle. Homework Equations F(E)=(k)(q1)(q2)/(r^2) The Attempt at a Solution...

Homework Statement A charged ball of mass 0.2[gr] and q=6E-9[Coulomb] hangs on a string between 2 plates that are 5[cm] apart. the ball makes 300 with the vertical. what is the voltage difference of the plates. Homework Equations Electric field: $$E[\frac{N}{Coulomb}]=\frac{V}{S[m]}$$ The...

Mod note: Below is a revised version of the problem. 1. Homework Statement Determine E at (x,0,0) where x>a/2. What is the asymptotic field on the x-axis? Homework Equations 1)Coulomb's law for charged surface of density Sigma ##\vec E(\vec x-\vec x')=\frac{\sigma}{4\pi\epsilon_0} (\iint...

Homework Statement Hello, I have to calculate the self-energy of an uniform charged electron with radius R. The distributed charge is e. Homework Equations The SE is given as: E=\frac{1}{2}\int dV \int dV' \frac {\rho(\vec r)\rho(\vec r')}{ |\vec r - \vec r'|} according to the problem sheet...

Homework Statement A charge of 4.1 nC is placed uniformly on a square sheet of nonconducting material, with side 19.0 cm, that lies in a horizontal plane. 1. What is the magnitude of the electric field just above the center of the sheet? The same charge is placed on a horizontal square...

Homework Statement A disk of radius 10 [cm] is charged with 5E-9 [Coulon]. where on it's axis is the greatest electric field. Homework Equations The field on the axis of a charged disk: ##E=\frac{1}{4\pi\varepsilon_0}\frac{q\cdot \cos\alpha}{s^2}## The Attempt at a Solution I express...

Homework Statement Show that the Lagrangian $$ L = \frac{m}{2}(\dot{r}^2 + r^2\dot{\theta}^2 + r^2\dot{\phi}^2sin^2\theta) - qg\dot{\phi}cos\theta $$ describes the motion of a charged particle (mass ##m## charge ##q##) in the magnetic field ## \vec{B} = g\vec{r}/r^3## (##g## is a constant)...

Hello. I was taught that a charge which changes its velocity must radiate (at least, in classical electrodynamics). Let's consider a charged particle which decays into another charged particle (and, maybe, others neutral particles; but not photons). In this case, can we find electromagnetic...

Homework Statement A conductive ball of diameter 0.4 [m] is charged equally with a concentration of \sigma=8 [micro-coulon/m^2]. What's the total number of electric field power lines, N, that extrude from the ball Homework Equations The electric field near a conductor is like in a capacitor...

[FONT=Times New Roman]Dear all, I have inquiries about the Bohr's calculation for energy loss of charged particles. These inquires are from the "Techniques for Nuclear and Particle Physics Experiments" (W.Leo). On page 23 of this book, it is written that: [FONT=Times New Roman]the the...

Hi all I gather a normal black hole has maximum angular velocity at the point that the event horizon is moving at The speed of light. However what would be the maximum rotational velocity for a maximally charged black hole- for example one made purely of electrons? Thanks

Homework Statement A velocity selector uses a 64mT magnetic field perpendicular to a 28kN/C electric field. At what speed will charged particles pass through the selector undeflected? Homework Equations v = E/B The Attempt at a Solution [/B] Using dimensional analysis, I converted units T...