1. ### I What are the potential effects on electricity due to Earth's magnetic field reversal?

What is/are the potential or theoretical effect on electricity due to reversal of planetary magnetic field? Would circuitry continue to function or would knowledge and understanding need re-evaluating as a result of a reversal of our magnetic field on planet Earth? Note: this is not a homework...
2. ### Lenz's Law for a rotating PM motor rotor spinning in a thin CU tube

The motor is required to operate at its resonance frequency and I am looking to add a thin-walled (0.010") copper tube inside the stator bore to add some damping. The current motor air-gap is 0.015". If I install a copper tube in the stator bore bonded to the stator and leave a 0.005" air-gap...
3. ### Force on a magnet in a magnetic field

So I'm kinda stumped. I'm assuming that since ##\vec{m}||\vec{B}##, the x and y components of both are zero. But I'm unsure how to take this further.
4. ### A Imperial-Metric Unit conversion for Magnetic Field Gradiometer?

Hi all, I have a question which I think should be a simple solve for most people but I cannot seem to get my head around it. It is a common case in geophysical surveying that a magnetic field vertical gradiometer might be used. This instrument uses two magnetometers separated by a known...
5. ### Coupled inductor boost converter - Ripple current

I am trying to calculate the ripple current in boost converter for ∆i1 and ∆i2 between time intervals between DT and T, and also dependent on the voltage level (Vin or Vin-Vout). To find a formula for ∆i1 and ∆i2, two formulas have to be derived for them. This is done from the equation: I...
6. ### B Magnetic Gears For Power Transmission

This thread is an attempt to better understand the pseudo direct drive, or PDD, gear. What I do know is it's made up of a set of magnets which can serve the function of a reducer- a basic diagram of it as well as a video can be seen below. In this mechanism, the inner rotor is the input while...
7. ### Load line analysis in femm4.2

Dear Forumers, This question is about load-line analysis for loudspeaker driver magnetic circuits in FEMM 4.2 (Finite Element Method for Magnetics), I can't seem to get an answer from the mailing lists. I would like to get the permeance coefficient for random points inside the magnet. I have...
8. ### Finding the magnetic field of a wave from the E field

Homework Statement Many sources of electromagnetic waves (stars and light bulbs, for example) radiate in all directions. A simple example of the electric field for a monochromatic electromagnetic wave produced by a spherical source is E(r,\theta,\phi,t)=A\frac{\sin \theta}{r} \big(\cos...
9. ### I Creating a Maglev Track using Electromagnets?

Hi All, I was wondering how I would go about creating a circular maglev track using electromagnets? The idea is to have more control over it and to eventually write a piece of code that would allow changes in the strength of the magnetic field potentially? I was just wondering how it would work...
10. ### A Problem In Electromagnetic Phenomena

Homework Statement [/B] In a thin rectangular metallic strip a constant current I flows along the positive x-direction, as shown in the figure. The length, width and thickness of the strip are l,w and d, respectively. A uniform magnetic field B is applied on the strip along the positive...
11. ### Will ferromagnetic dust retain magnetism in molten aluminum?

Curie temperature for magnetite is 858 C, for iron 1043 C. Duralumin melting point is about 630 C. Does this mean that if I take a small silicone mold, place a magnet underneath it, add ferromagnetic powder to the mold and then pour molten aluminum in, I will get the aluminum detail with...
12. ### Question from JEE (Magnetics)

Homework Statement A particle of charge q and mass m is projected on a rough horizontal plane (X-Y) from a point (a,0,0) with initial velocity v = V j . In space there exists uniform electric and magnetic field E k and -B k respectively. Acceleration due to gravity is g and friction coefficient...
13. ### Velocity of current-carrying cylinder

Homework Statement A cylindrical rod of length w carries a current I as shown(perpendicular to B) and is bathed in a field B perpendicular to the plane in which is a " shaped rail. The rod rolls without slipping on the rails, its length perpendicular to the two parallel rails and equal to the...
14. ### Capacitor with magnetic dielectric

Odd question, would anybody know what would happen if a parallel plate capacitor (good conductor) had a soft magnetic material (fairly poor conductor) as a dielectric? What would be the DC/AC electrical characteristics of this?