Basic Question

[Asimov]

Hi,

Have small question about basic electric theory concerning induction.
For example I know that a wire moving through a magnetic field will
induce an emf. However will an electric field also induce an emf if a
wire moves through it? Would this effect be what makes fluorescent
lamps glow underneath power distribution lines?

Asimov
******

.... Just a little force field zap.

 

[Nigel]

"Asimov" <Asimov@-removethis-bbs.juxtaposition.dynip.com> wrote in
news:MSGID_1=3a167=2f133.0_4068fccd@fidonet.org:

Hi,

Have small question about basic electric theory concerning induction.
For example I know that a wire moving through a magnetic field will
induce an emf. However will an electric field also induce an emf if a
wire moves through it? Would this effect be what makes fluorescent
lamps glow underneath power distribution lines?

Asimov
******

... Just a little force field zap.

A fluorescent tube works by an electric field inside the tube causing a
discharge, and this electric field can come either, as normally, from
applying a mains voltage across the tube, or from the electric field
produced by a power line. So fluorescent tubes will produce a visible glow
under a power line, though usually it is only visible after dark as it is
much weaker than the light they normally produce. The current through a
fluorescent tube under a power line would probably be 20 – 200 microamps
(ľA) depending on the field. This is much less than a person can normally
perceive, so you can hold the tube yourself under the power line without it
hurting. (For comparison, a 10 W tube at 230 V draws 40 mA – 200 times
greater). You can sometimes also make a fluorescent tube produce visible
flickers by holding one end and rubbing your foot on a carpet to generate
static electricity, though again, this needs to be done in a dark room.

http://www.emfs.info/sci_EffectsOnEquip.asp


Electromagnetic Induction info

http://makeashorterlink.com/?A24A431E7

A Google search or a decent textbook should also help.