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: Right hand rule confusion

  1. Oct 8, 2011 #1
    for the right hand rule for a wire with a current and magnetic field. Your thumb points in the direction of the current and you wrap your fingers around the wire. Do your fingers form a fist or how much do you curl it? Right now, I'm curling my fingers where the tips of my fingers TOUCH my palm and that gets me the right answers. Is that how it's down?
  2. jcsd
  3. Oct 8, 2011 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    The point of grabbing the wire with your right-hand is to indicate
    the sense of the magnetic field...

    Specifically, a given point in space,
    the magnetic field due to a long straight wire is
    pointing tangent to a circle through your point and centered at the wire.
    Which way along the circle (clockwise or counterclockwise)?
    The way your right hand grabs the wire (with thumb along the positive current) indicates which way.
    (It doesn't matter how much you curl it... The point is that your right hand can only curl in one direction.)
  4. Oct 8, 2011 #3
    yeah but how much do you curl your finger? All the way?
  5. Oct 8, 2011 #4

    Ray Vickson

    User Avatar
    Science Advisor
    Homework Helper

    It doesn't matter. Curl them all the way if you want; don't curl them at all if you prefer. The answer is still the same: you get the ORIENTATION of the magnetic field, not necessarily the detailed direction.

  6. Oct 8, 2011 #5
    a problem that I had to do dealt with a wire. The problem was that a wire is located at y=6m that is 2m long and the current is flowing towards the +x direction. It wanted to know whether the magnetic field was +/- at x=0. I had to curl my hand all the way to get that it was positive.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook