Mixer it was not intuative

Locke's picture

I did not find this intuitive, nor high school level. I bow to your high school. I admit I find it difficult to apply the right hand rule trying to figure out the positive and negative field calculations to the flow of B-field calculations. Since the currents are flowing in opposite directions the B-fields act against each other and are therefore additive. However, assuming a 2-D representation, and assuming a plane through the center of the wires parallel to the direction of the current flow.

B= mu*I/(2*pi*r) where mu is the permeability of free space, which is a constant of 4*pi X 10^-7 T*m/A, I is the current in Amperes, and r is the radius of the B field (in meters) where you want the calculation.

First, half of 1.1 inches is .55 inches, which is 0.01397 meters.

(B field from wire 1) = mu*5.6/(2*pi*0.01397) = 8.4466 x 10^-5 T

(B field from wire 2) = mu*16.6/(2*pi*0.01397) = 2.37625 x 10^-4 T

I come up with 3.2209 x 10^-4 teslas. If I am right, I want a glass of a nice red wine. If not, I owe you a beer of your choice.

Peace, and I ain't gonna do this one again.

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I have no idea Locke ... you are da man!
Mixer's picture
Submitted by Mixer on Tue, 07/24/2007 - 8:55am.

I have not worked a problem like that since my days in Tech School with the USAF at Shepard AFB or Goodfellow AFB in Texas (courtesy of Uncle Sam).

I did take Physics in undergraduate school but not in Grad School. I think I can still handle Ohm's law and the simple equations, but I would have to cheat like heck to get this one. I can set it up and give you the equation. But I am not going to attempt to work the problem.

The mere fact that you mention the right hand rule when dealing with the Electromagnetic Field tells me you remember more than I do. I recall the right hand rule telling you the direction of current flow I think. There was a time when I had to calculate EMF .... about 30 years ago.

I didn't pursue electronics as a career whenever we stopped to doing 'bench level' repair on electronics in the service. Of course, in the field it was good to know so we took classes for it; however, the newer and more advanced equipment gave error codes and would essentially trouble-shoot itself.

My favorite Physics problems were always the mechanical problems - velocity vectors, Mu (Coefficient of sliding friction), Impact, big 'G' and little 'g' problems and acceleration. I used to want to be involved in crime scene or wreck reconstruction .... I told myself when I got out of the military that I would pursue that line of work...but never did.

Good job - you win - you certainly deserve the wine at the least - but I am a tee-totaler so I can't take the beer anyway. Now, I have been known to enjoy a nice cigar now and then .... but that's another story all together.

In a totally unrelated note:

I am working on a blog to get your blood boiling ... one you can do without a calculator ... the kind we both enjoy.

Do you want to see some current examples of liberal media bias? Click Here.


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Mixer.. no rush
Locke's picture
Submitted by Locke on Tue, 07/24/2007 - 10:14am.

I'm traveling to the beach 'till Monday. Hoping I don't see Git in a speedo!

---------
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If you do....
Mixer's picture
Submitted by Mixer on Tue, 07/24/2007 - 10:25am.

...you will need a lot more than that glass of wine! Travel safely! Don;t forget your sun glasses Cool

I'll look for some topic to post by then.... it's a slow news week.

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