How Should the Magnetic Fields from Two Wires Combine at Point L?

In summary, the problem involves finding the magnitude of the net magnetic field created at point L by two wires located a distance d*sqrt2 from the midpoint between the wires. The solution involves finding the x component of the magnetic field and multiplying it by 2, which is done by multiplying the previous answer [(μI)/(2pid√3)] by the sine of theta, or d/(d*sqrt3). However, the correct answer is (μI)/(3dpi). The angle theta is defined as the angle between the line joining the two wires and the line joining the wire and point L, and can be calculated using the equation cosθ = d/d*sqrt3.
  • #1
Puchinita5
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0

Homework Statement



I upploaded a picture of the problem...

The part I'm stuck on asks this:
Point L is located a distance d sqrt2 from the midpoint between the two wires. Find the magnitude of the net magnetic field BL created at point L by both wires.


I had already solved that magnetic field produced by ONLY wire 1 at point L,
and found it to be (μI)/(2pid√3)

I realize that the magnetic field from wire 1 would be pointing up and to the right, whereas the magnetic field from wire 2 would point down and to the right. Therefore, I need to find the x component of the magnetic field and multiply by 2...

this is where I'm not understanding...so i took my previous answer, (μI)/(2pid√3), and figured i needed to multiply by cos theta, theta being the angle between the magnetic field and the x axis, in order to get the x component. This would be (d√2)/(d√3)...which doesn't give me the right answer...

I looked up the answer to this problem, and i see that they multiplied my answer by the SIN of theta, or d/(d√3)...but WHY?!

So i think the answer should be (μI√2)/(3dpi), but the correct answer is (μI)/(3dpi)

if anyone can tell me where my logic is wrong, i would greatly appreciate it because now I'm really confused! (and really frustrated LOL)




Homework Equations





The Attempt at a Solution

 

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  • #2
In the triangle formed by the wires and point L, the angle defined by is the angle between the line joining the two wires and the line joining the wire and the point L. In that case cos θ = ...?
 
  • #3
i'm not quite sure what you mean...i edited the photo attachment to show what I'm thinking of with theta and the magnetic field... ?
 
  • #4
Puchinita5 said:
i'm not quite sure what you mean...i edited the photo attachment to show what I'm thinking of with theta and the magnetic field... ?
In the attachment join 1 and L. This line is perpendicular to B. The angle θ shown in the figure is the same as the angle between the line joining the two wires and the line joining 1 and L. In that case cosθ = d/d*sqrt3.
 

FAQ: How Should the Magnetic Fields from Two Wires Combine at Point L?

What is a magnetic field?

A magnetic field is an invisible force field created by moving electric charges. It can be visualized as lines of force that surround a magnet or electric current.

How are magnetic fields created by two wires?

When two wires have electric currents flowing through them in the same direction, they create magnetic fields that interact with each other. The magnetic fields will either attract or repel each other, depending on the direction of the currents.

How do the distances between the wires affect the magnetic field?

The strength of the magnetic field created by two wires is inversely proportional to the distance between them. This means that as the distance between the wires increases, the strength of the magnetic field decreases.

How can the direction of the magnetic field be determined?

The direction of the magnetic field can be determined by using the right-hand rule. Point your right thumb in the direction of the current flow in the first wire, and your fingers will curl in the direction of the magnetic field.

Can the magnetic field from two wires cancel each other out?

Yes, it is possible for the magnetic fields created by two wires to cancel each other out. This can occur when the wires have equal currents flowing in opposite directions and are placed at equal distances from a point of interest.

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