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: Magnetic field particles

  1. Apr 22, 2008 #1
    steams of charge particles emitted from the sun during periods of solar activity creates a disturbance in the earth's magnetic field. How does this happen?

    also, the text in our book discussed the magnetic field of an infinitely long, straight conductor carrying a current. Of course there is no such thing as infinitely long anything. How do you decide whether a particular wire is long enough to be considered infinite?

    I really dont know how the answer these questions..pls help....lotsa thanks!!
  2. jcsd
  3. Apr 22, 2008 #2
    Think of the definition of a current. A current causes a magnetic field, can you imagine how this might interact with the earth's field.

    Objects are considered infinite when the length is so much greater than the lengths in question that it is insignificant what is happening far away. For example, a wire that is 100 miles long looks infinite to an ant. Actually the wire probably won't even need to be that long to appear infinite to the ant.
    Last edited: Apr 22, 2008
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook