Magnetic field = 0 inside a conducting wire?
Hey. If a wire is conducting electricity and all the current is concentrated at the edge of the wire, as in the skin effect, the magnetic field everywhere inside should be zero due to symmetry when...
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Voltage measured across a capacitor with embedded charges
Hi all, Lets consider the situation illustrated in the attached figure. A permanent surface charge density [itex]\sigma[/itex] is embedded in between the two metallic electrodes of a capacitor....
View ArticleUncertanity Principle in Macrocosm
A Macrocosm thing, example a car, can be exist two different places in the same time ?
View ArticleStopping distance increased by how much?... with a mass increase
Hello have a question and am interested to find a simple equation to include mass as a variable regarding stopping distances of a car In the UK highway code..... a braking distance = 14m for a car at...
View ArticleApplying refractive index
Quick question if E_0+E''_0=E'_1+E''_1 why is n_0(E_0-E''_0)=n_1(E'_1-E''_1) Many Thanks in advance
View ArticleConfusion on Continuity of Current and Free Charge in Conductor
I know there must be something wrong with the following derivation based on Maxwell's equations but could not figure out what is wrong. The derivation deals with continuity of current and free charge...
View ArticleMissing mass in gravitational force
This is a really dumb question but I can't seem to make sense out of this... For a conservative force, we have [itex]\vec{F}=-\nabla \phi[/itex], where [itex]\phi[/itex] stands for the potential. So...
View ArticleDefinition of current
This is a very sound stupid question, but I'll go ahead anyway. Current is defined as the displacement of charge through a cross-section of a conductor per unit time. Okay. But how does relate to its...
View ArticleElectric field
In an irregular shaped charged conductor will the electric field E at all points within the conductor be zero? If yes, then how?
View ArticleConservation of Angular Momentum?
Sorry about the crude drawing but here's the question. If you have a ball in a hollow pipe, which is being rotated around one of it's ends. Why does the ball leave the pipe? I would think that the...
View Articletextbook reading about cyclotrons
Hello, I was looking at my textbook reading about cyclotrons, and I was confused about the Dees, as well as why is there a space in between the Dees? What measurement is made within that space between...
View Articlespecific heat capacity
Now consider two objects,A and B. A has a higher specific heat capacity that B. When both object is subjected to same amount of thermal or heat energy, rise in temperature in A is lower as our common...
View ArticleAC circuits - Complex vs Ordinary notation
When doing calculations on AC circuits, what is in your opinion the best notation? Here they mostly use complex notation. For example: V(t) = Vmaxeiωt. In US textbooks (at the non-EE level), they only...
View ArticleFaraday's law. Induced electric field.
When you use Faraday's law to calculate the induced electric field due to a changing magnetic flux, you integrate over a loop defined by the circuit you're interested in. Why is the electric field...
View Articleimpedance for RLC circuits
Hey. Say you have an RLC circuit with an AC supply. Then I=ei(ωt-α). My question is: will α always exist, ie will the current always be phase-shifted compared to the voltage, as long as the impedance...
View ArticleHow to drop terms in a Lagrangian?
Hi guys, So textbooks have it that: "Two Lagrangians differing by a total time-derivative of a function of the coordinates are equivalent". I have no idea what that means or how to use it; so I dont...
View ArticleBullet deceleration due to drag
My friend and I are working on a realistic FPS sniper simulator and we wanted to be able to realistically model things like bullet drop, flight time, and impact energy. I've managed to find the drag...
View ArticleStable oscillation of a blanket in a dryer?
Hi everyone, Today I noticed something curious while I was drying a blanket in a dryer. The dryer was turning and the blanket was jumbling around as usual, but then I realized the motion was...
View ArticleCouple of Questions Regarding EM Waves
I'm a little unsure of my own answers to these questions. Hopefully I'll clear up my misconceptions. 1. If I measure the E-field and B-field at a point in space where there is an EM wave, would I be...
View ArticleCalculating Flux for non-lambertian emitter
Hey everyone! I am struggling with the following problem: I am calculating the ratio of photons emitted to electrons generated in an LED. Due to the architecture the device shows a strong cavity effect...
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