How Does a Current-Carrying Wire Affect a Nearby Compass?

[thename1000]

A long current-carrying wire, oriented North-South, lies on a table (it is connected to batteries which are not shown).
A compass lies on top of the wire, with the compass needle about 3 mm above the wire. With the current running,
the compass deflects 12 degrees to the West. At this location, the horizontal component of the Earth's magnetic
field is about 2e-5 tesla.

What is the magnitude of the magnetic field at location A, on the table top, a distance 2.7 cm to the East of the wire, due only to the current in the wire?

Thanks!

 

[learningphysics]

First find the magnetic field due to the wire alone in the first part... remember that the Earth's magnetic field is oriented north to south... and you are given the magnitude... and you're given the direction of the net magnetic field...

when you get that, you can get the current in the wire... and hence you can get the magnetic field any distance from the wire...

 

[TVP45]

What are your latitude and longitude? What is the date?