1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Help please? I dont get this one?

  1. Oct 4, 2007 #1
    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?

  2. jcsd
  3. Oct 5, 2007 #2


    User Avatar
    Homework Helper

    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...
  4. Oct 5, 2007 #3
    What are your latitude and longitude? What is the date?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook