Blog Entries: 2

## Electromagnetic waves

so basically i was considering the speed of the charges inside wire defined by the drift velocity and speed of electric waves that's equal to speed of light..so my point is if electric waves don't carry any charge (as mostly light that we encounter from sun's radiation is em and since they don't carry any charge we don't get shock)so what do they actually carry..i was trying to figure out its resemblance to mechanical waves ..as mechanical wave don't itself carry any matter with it they only transfer energy..then so do the electric waves they can't carry charge but they must transfer energy in the form of you know electric waves..or could i say now that these electric waves are source of electric field..then thing that's confusing me is that if electric field propagates at speed of light(speed of electric waves)..then do the voltage that we define as eL or voltage or potential at a point is=electric field intensity * L(distance) then should the voltage drop or potential also varies accordingly or i could say that the potential also following the electric field intensity at the speed of light..but this is contradictory to our general observation in which we define particular time period and phasors which define variation of voltage that..so not at the speed of light..

 Recognitions: Gold Member Light itself is an electromagnetic wave that carries energy with it, just like all waves do. As for the velocity of electric fields inside conductors, I believe that is less than c, but I don't know any details on it.
 Good day, i have a different question... I need a core for an Electro Magnet which will be able to be as strong as possible when it has a current applied, but will not be attracted to a permanent magnet when the current is turned off. The core must lose its magnetic properties as soon as the current is removed so that it can be switched on and off. (i.e. Steel can become a strong electro magnet, but will be attracted to a permanent magnet with or without a current, therefore I cannot use it.) To make the experiment work as effectively as possible the core should be able to be converted to an electromagnet with minimal current, I thought about using Ferrite (Manganese Zinc) Round Bar? What will be the best gauge to use to get a strong magnet, but keep the current "voltage" as low as possible, even if is not as strong, i only require it to react with a neodymium magnet from a distance of at least 50mm - 100 mm. Do you have any suggestions on this topic?
 Recognitions: Gold Member WJE your best bet is to make a new thread with your question.