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## Homework Statement

The compass settles at 45 degrees to the NS direction of the earth's field and to the wire it is next to(picture a compass next to a straight upwards wire with a current reduced until the compass points 45 degrees from the current perpendicular to earth's mag field at either north or south). The current measured is 0.731A, and the volts put through it is 2.5V.

Calculate the magnitude and direction of the magnetic field from the current at the compass position (45 degrees). There are five loops of wire.

Also, show the vector diagram of the two magnetic fields and the resultant field (you know the size and direction of the field from the wires, and the angles of the earth's field and the resultant field.) What is the earth's field form your measurements?

## Homework Equations

B=u

_{0}I/[2(pi)r]

maybe F=qvBsin(theta)?

## The Attempt at a Solution

I used the B=u

_{0}I without the 2(pi)r because no measurements of the wires nor area were given. Using B=uI x 5, I got the answer 4.59 x 10

^{-6}T going clockwise.

The vector diagram would show the wire's field going east while the earth's field is going south. I'm completely clueless on the earth's field measurements.