# Finding the magnetic field

1. Homework Statement

Two parallel wires are 5.60 cm apart and carry currents in opposite directions, as shown in the figure.

Find the magnitude of the magnetic field at point P due to two 1.50-\,{\rm mm} segments of wire that are opposite each other and each 8.00 {\rm cm} from P.

2. Homework Equations

3. The Attempt at a Solution
I don't know what to us for r or i'm using the wrong equation

but i used muenot Itop/(2pi r) + muenot I bottom/(2pi r) where r was the sqrt(8^2 +8^2)
1. Homework Statement

2. Homework Equations

3. The Attempt at a Solution
1. Homework Statement

2. Homework Equations

3. The Attempt at a Solution
1. Homework Statement

2. Homework Equations

3. The Attempt at a Solution

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I think you should use the Biot-Savart Law.

Find the magnitude of the magnetic field at point P due to two 1.50-\,{\rm mm} segments of wire that are opposite each other and each 8.00 {\rm cm} from P.
Can you rephrase that line so it is readable? I don't know what they are asking now...

If they're asking the magnetic field for only small segments of the wire than yes, use Biot-Savart.

If they're asking the magnetic field for large segments of the wire (nearing infinite in relation to the other distances) then you can probably use Ampere's law ( int B * dl = ...)

got it

I can't post pics yet. but i got it anyway I was using the wrong thing for r on each magnetic field.