Force Between Two Concentric Solenoids
Imagine a finite length solenoid with outer radius R1 and inner radius R2. This solenoid has a time-varying current going though it. This solenoid is also fixed so that it cannot move. Now imagine...
View ArticleRelating physics forces and entropy
Consider proton and electron are seperated in space at some finite distance.Now suppose they released then the decrease in potential energy equals kinetic energy but as electrons or protons are...
View ArticleRadiation from a charged harmonic oscillator
Anyone know if there are any graphical simulations online for the field of a charged harmonic oscillator, or better yet maybe some kind of paper on it?
View Articlewhy is dielectric breakdown damaging?
Dielectric break down... i understand that there is current passing through the insulator but why is this damaging to the insulator? please go as deep as you can. thankyou
View ArticleFLUXGATE magnetometer - how it works
Assuming that I am looking at an 'ideal' fluxgate magnetometer. I am feeding this transformer an ideal sine wave. The secondary winding output and the primary winding input are fed into two channels of...
View ArticleDiffusion equation with an external force
I thought I would do a little physics for fun, since it has been over 20 years since I last did any. I picked up Sethna's Stat Mech book. He gives a derivation of the diffusion equation that goes as...
View Articlewhere the energy goes.?
Flyheel the storage energy. The transfer from mechanical energy to electric energy was equal. The situation was, i got a 1/2 hp electric motor (EM) that can turning a 5 kg flywhell (∅ 28 cm) to 1500...
View ArticleIs the electric field inside a circuit non-conservative?
As charge moves around a circuit, their energy increases by each loop. However, I just heard somebody say the total electric field inside a circuit is conservative. How is that possible? Is the field...
View ArticleFunction multiplied by its complex conjugate
Hi Guys, I have two questions which kind of relate. The first relates to the complex conjugate of a function. Specifically, When a function is multiplied by its complex conjugate, what does that mean...
View ArticleQuestion about an electron beam traveling through static B-fields
In the figures below is a sketch of an electron beam entering alternating static magnetic fields perpendicular to that of the motion of an electron beam. This beam is injected from a 45° angle below...
View Articleconfusion about Noether's theorem
Hi, I keep running my brain in circles while trying to get a solid grip on Noether's theorem. (In Peskin and Schroeder they present this as a one-liner.) But I'm having trouble seeing the equivalence...
View ArticleUnits for flux density
While I do understand the use for the displacement vector D = (e0)E + P, I don't quite understand why they label it as "flux density". The units for the displacement vector are C/m^2. The units for...
View ArticleSymmetry and electric fields
Hey. Let's say you have an infinitely wide and long disk with a thickness h. Inside the disk, there is a constant charge density ρ0. Why would the electric field lines be perpendicular to the disk? Can...
View ArticleThin walled polymer balloon deflection
Hi, I am designing an inflatable balloon (long and thin like those used to make balloon animals) with a purpose to support a force in a manner like a cantilever. I am struggling to find...
View ArticleThermionic emissions in magnetrons (amount of electrons emitted)
I was wondering how many electron are emitted by the cathode during thermionic emission in a magnetron and how you would calculate this(how to calculate the amount of electrons emitted), I was also...
View ArticleI need some intuition for various EM phenomena
I am using a computational electromagnetics software that solves for the resultant electric and magnetic fields around materials represented as lattices of discrete dipoles. Some of the results are the...
View ArticleFrame of reference - forces in a turn (airplane)
Hi, I've seen the forces in a turn depicted two different ways: http://selair.selkirk.ca/Training/Ae...es/lf-turn.gif http://www.free-online-private-pilot...uring_turn.gif Which one is correct? I think...
View ArticlePotential Gravitational Energy into Force
How do you derive the equation for gravitational force from the eqauation for potential gravitational energy: e=-Gm/x? For me it seems as though you take the derivative and that would work, but i don't...
View ArticleSeeking Affordable Raytrace Software for Throughput
This is somewhat of an extension of tosik's recent post. I work a bit with weak optical signals for PMTs and spectrometers and I am always trying to optimize the light collected by a system. Galilean...
View ArticleKinetic rotational energy of a bar hooked to a coil
I have solved an exercise and I'd like to know if my proceeding about finding kinetic energy is correct or not, because this is the first time that I "meet" a situation like this. "A bar has mass M and...
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