| Topic: |
Science > Physics |
| User: |
"Sanny" |
| Date: |
04 Jul 2006 01:27:44 PM |
| Object: |
I am confused with Magnetic theory |
When I learn Electric field theory
E=e0 * (Q1 * Q2)/r^2
We had e0 coefficient Where E is the electric field, Q is the Charge
and r is the distance from charge
But When we work on Magnetic field I do not understand why we take e0 =
1
E=1 * (i1 * i2)/r^2
Why does when computing force on a wire carrying current i1, in
Magnetic Field we make e0=1.
I asked my Teacher in School, He said this is the formula you just
remember it. But does anyone knows how we make it "1"
Thanks
Sanny
Play Chess at: http://www.GetClub.com/Chess.html
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| User: "FrediFizzx" |
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| Title: Re: I am confused with Magnetic theory |
04 Jul 2006 02:54:45 PM |
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"Sanny" <softtanks@hotmail.com> wrote in message
news:1152037664.806611.182310@a14g2000cwb.googlegroups.com...
When I learn Electric field theory
E=e0 * (Q1 * Q2)/r^2
We had e0 coefficient Where E is the electric field, Q is the Charge
and r is the distance from charge
But When we work on Magnetic field I do not understand why we take e0
=
1
E=1 * (i1 * i2)/r^2
Why does when computing force on a wire carrying current i1, in
Magnetic Field we make e0=1.
I asked my Teacher in School, He said this is the formula you just
remember it. But does anyone knows how we make it "1"
What grade are you in? Everything that you have presented looks wrong.
Wanna try again? Empirically, the electric constant, k_e, and the
magnetic constant, k_m, for the "vacuum" is found to be related by,
k_e/k_m = c^2/2
where c is the speed of light. I am assuming your e0 is k_e and your
first expression should really be force between two charges not electric
field. Maybe this will help if you study it carefully,
http://www.ee.surrey.ac.uk/Workshop/advice/coils/unit_systems/
FrediFizzx
Quantum Vacuum Charge papers;
http://www.vacuum-physics.com/QVC/quantum_vacuum_charge.pdf
or postscript
http://www.vacuum-physics.com/QVC/quantum_vacuum_charge.ps
http://www.arxiv.org/abs/physics/0601110
http://www.vacuum-physics.com
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| User: "Martin Hogbin" |
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| Title: Re: I am confused with Magnetic theory |
06 Jul 2006 03:27:02 AM |
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"Sanny" <softtanks@hotmail.com> wrote in message news:1152037664.806611.182310@a14g2000cwb.googlegroups.com...
When I learn Electric field theory
E=e0 * (Q1 * Q2)/r^2
We had e0 coefficient Where E is the electric field, Q is the Charge
and r is the distance from charge
But When we work on Magnetic field I do not understand why we take e0 =
1
E=1 * (i1 * i2)/r^2
Why does when computing force on a wire carrying current i1, in
Magnetic Field we make e0=1.
I asked my Teacher in School, He said this is the formula you just
remember it. But does anyone knows how we make it "1"
The answer to your question is choice of units. In your first
equation (which I presume is meant to be the force between two
charges) you could change the value of e0 by changing the
units in which you measure charge. You can pick units
of charge such that e0 becomes 1.
I am not quite sure what your second equation is but it
would seem that, in the system of units you are using
the constant of proportionality is1.
Martin Hogbin
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| User: "Sue..." |
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| Title: Re: I am confused with Magnetic theory |
04 Jul 2006 02:49:03 PM |
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Sanny wrote:
When I learn Electric field theory
E=3De0 * (Q1 * Q2)/r^2
We had e0 coefficient Where E is the electric field, Q is the Charge
and r is the distance from charge
But When we work on Magnetic field I do not understand why we take e0 =3D
1
E=3D1 * (i1 * i2)/r^2
Why does when computing force on a wire carrying current i1, in
Magnetic Field we make e0=3D1.
I asked my Teacher in School, He said this is the formula you just
remember it. But does anyone knows how we make it "1"
<< Relative permeability, sometimes denoted by the symbol =B5r, is the
ratio of the permeability of a specific medium to the permeability of
free space =B50: >>
http://en.wikipedia.org/wiki/Permeability_(electromagnetism)
So when the specific material IS free space, its ratio to free space is
1=2E
Sue...
Thanks
Sanny
=20
Play Chess at: http://www.GetClub.com/Chess.html
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| User: "The Real Chris" |
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| Title: Re: I am confused with Magnetic theory |
04 Jul 2006 04:46:08 PM |
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just for fun make it 1 if you really like it make it 2.
"Sanny" <softtanks@hotmail.com> wrote in message
news:1152037664.806611.182310@a14g2000cwb.googlegroups.com...
When I learn Electric field theory
E=e0 * (Q1 * Q2)/r^2
We had e0 coefficient Where E is the electric field, Q is the Charge
and r is the distance from charge
It is called the permittivity of free space to give a consistant set of
uits. The force for example is measured in newtons (it might be pounds force
in america or even poundals one or two european probes got lost because of
these sort or errors the actual value depends on the engines being
rocketdyne or boing mind you aerospacial use newtons but rolls royce still
use dynes, I think that engineer should retire. a real joker uses kilograms
force, it a real hokus pokus in america mission control they've not heard of
system International must be because it is French and all our screws are
mertic M 3 --- but in america you've got american standard fine and others
depending if it is the pitsburg screw factory or the meapolis threading
vault, in Russia it all cm but a moscow cm is bigger than the omsk cm and
vladivostok cm is difficult to define. Omsk Fabrica 1 turrent gun wont fit
Omsk fabrica 3 shells and so it goes on.
So the value you use for e0 will vary depending on the unit of force you
use.
But When we work on Magnetic field I do not understand why we take e0 =
1
E=1 * (i1 * i2)/r^2
it should by u0 (greek mu 0)
the value is used for convenience but in si units it is quite a small value
much less than one.
Why does when computing force on a wire carrying current i1, in
Magnetic Field we make e0=1.
I asked my Teacher in School, He said this is the formula you just
remember it. But does anyone knows how we make it "1"
Thanks
Sanny
Play Chess at: http://www.GetClub.com/Chess.html
Actually 1 is quite easy, if you want to make it difficult use 4*pi*10E-7
for e0 and use e0*u0=c to get u0.
Chris.
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