Electromagnetic force Definition and 76 Threads

Hello, Recently I have learned that magnetism causes the Lorentz force. The electric force makes sense to me in terms of virtual photons. But how do virtual photons give rise to magnetism and the Lorentz force. Is it because when the charged particle moves through an magnetic field it comes...

Homework Statement 1.Calculate the work done by the force F=i cos(pix/4) + j y2 along the path y=x2 in the x-y plane from (0,0) to (2,4). 2.Is the force F conservative? Explain. Homework Equations Work = Integration between a and b of F.dl The Attempt at a Solution 1. I know...

the title is pretty clear, so we have this F=q( E+V/c X B) the force for a point charge q in an electromagnetic field. and we have the formula to the hamiltonian of electromag force: H= (P+ q/c.A)/2m _ e\phi. the question is how can I get the F from the hamilton principle, using the...

While a magnet is moved toward the end of a solenoid, a voltage difference is induced between the two ends of the solenoid wire and a current flows (case of closed circuit), however there is no existence of electromagnetic force (Laplace force) though we have current traversing the solenoid in...

i was just wondering ,what is the 'best' way to route electromagnetic force? some wire wrapped round the core? or an electric reed switch or something else, the electricity generated lights a bulb. it seems to me that a reed switch takes up less space and many of them can be added aso its...

Homework Statement Can anyone tell me what are the different types of electromagnetic forces? i know friction, non-penetrability of solids etc. are phenomenons of the electromagnetic force. Similarly are viscous force, cohesive force, adhesive force results of electromagnetic force...

so, i was told FM= qV + B sin\theta, where \theta=90 in order to get the full magnitude of the force but why is the electromagnetic force perpendicular to B? also, looking upon the right hand rule, if the positive charge is heading towards you, and subsequently the magnetic field is then...

Consider an infinitely long straight conductor carrying a current. Let's assume that the free charges in the conductor are positive and are moving at a drift velocity v. Now, consider a particle of charge +q also moving with v in the same direction as the current at a distance r from the...

Hi! I'm new to the forum and could really use the help. I am trying to determine the formula to use in order to establish the force needed for two electromagnets to repel a distance of 0.5mm if each is 1.5mm in diameter. Also, how to calculate the total electromagnetic force between X number of...

I've heard that accelerating charge generates photons. How do the photons create electromagnetic force, how do they differentiate between positive and negative charges, and how would electromagnetic force work in the case of stationary particles? Are electrons so much more densely charged...

Hi, I understand that force due to an electromagnetic field on a surface can be calculated by F = \oint {T . n dS} where T is Maxwell stress tensor. http://en.wikipedia.org/wiki/Maxwell_stress_tensor" And this tensor consists of E_x, E_y, E_z, H_x, H_y, H_z I don't understand how...

It is written over here http://www.particleadventure.org/electromagnetism.html that, "...the force that keeps you from falling through the floor is the electromagnetic force which causes the atoms making up the matter in your feet and the floor to resist being displaced." Can anyone explain...

Yes, gravity is WAYYYYYYYYYY weaker than the electromagnetic force in the quantum world, BUT when we talk about the big picture, the universe is held together by gravity. So... in that transition from the micro to the macro, can anybody tell me at what scale, roughly, the gravitational force...

Purely from a non-mathematical perspective, could some/any/every-body answer my questions on the electromagnetic force in extra dimensions? άλφα) I am curious about how in the old Kaluza theory of the electromagnetic force the equation, which he found from his equations worked when it...

Suppose we take there are one electron and one proton, they attract each other by exchange of virtual photon of energy ∆E and it exists for ∆t. From where virtual photon gets energy ∆E? Is it from electron or proton?if it gets energy from electron or proton, will the energy of electron and...

force between two charges is it electric force or electromagnetic force? And force between the atom nucleus and the electron is it electric force or electromagnetic force? how

According to Coulomb's law we have that the force between two charged particles could be described by (1)~~~F = k \frac{Q_1 Q_2}{r^2}. Now, a force is according to most sources something that causes a mass to accelerate (not a charge to accelerate), so the force in (1) above will...

1. I'm doing a lab involving electromagnetic force. In the lab I stroked two pieces of clear plastic that were lying on a table. When I held the two pieces of plastic up in the air near each other, they were attracted to one another. I don't understand why at all? Any ideas?! Did I give...

When current is allowed to flow through an electric conductor, magnetic fields are produced. What actually causes the magnetic fields to appear? :smile:

how can wec trace the origin of push and pull to electromagnetic forces? I mean when we push a thing what actually are we doing? What are the atoms at the contact surface actually doing?

hi can you please tell me what is reverse electromagnetic force? thankz!

A simple question but one I personnaly find difficult. Why do we need a photon to mediate the electromagnetic force?

Hi I have some problem to get insight into the mediation of the electromagnetic force and hope someone here is able to help me. If you look at the Standard Model there is the photon which acts on electrically charged particles like electrons and quarks. The electromagnetic force is...

Suppose we have a DC motor with permanent magnet. Moreover, the armature of motor is groove rotor. The elementary electromagnetic force is given by: dF=jxBdv, where j is electric current density , x is vector multiplication , B - magnetic flux density , dv - elementary volume. If we integrate...

What is the magnitude of the force on the proton in the figure? The figure is in the link below. http://img207.imageshack.us/img207/5842/untitled9xb.png I have tried the Lorentz Force law that F = q(E + v x B) and got a numberical result of 4.8*10^-13 N, but that is wrong.

I hope my question makes some sense; if not, just post an "evil smiley" and ignore it :smile: So, my only "knowledge" about this is based on one of Hawking's books, wherein it is written: If space had four dimensions instead of three, gravitation would behave differently (I think it was...