1. Not finding help here? Sign up for a free 30min 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!

Moving Charges and Magnetism Problem

  1. Aug 16, 2014 #1
    1. The problem statement, all variables and given/known data

    Two particles A and B having equal charges +6C, after being accelerated through the same potential difference enter a region of uniform magnetic field and describe circular path of radii 2 and 3cm repectively. The ratio of mass of A and B is ______

    2. Relevant equations

    Force on the particle in a magnetic field = Bqv

    In a circular path, mv^2/r = Bqv
    →r = mv/Bq

    3. The attempt at a solution

    I don't know if I should consider their velocities to be equal.
    If the velocities are equal, the r(A)/r(B) = 2/3 which is incorrect.
     
  2. jcsd
  3. Aug 16, 2014 #2

    TSny

    User Avatar
    Homework Helper
    Gold Member

    Hello, anraphy. Welcome to PF!

    Do you know how to relate the final speed of a particle to the potential difference through which it is accelerated?
     
  4. Aug 16, 2014 #3
    Potential Difference and Velocity

    E = Vq
    →0.5mv^2=Vq
    →v = √(2Vq/m)
    OR
    →V=0.5mv^2/q

    where
    V-potential difference
    m-mass of the particle
    v-velocity of the particle
    E-energy of the particle
    q-charge on the particle
     
  5. Aug 16, 2014 #4

    TSny

    User Avatar
    Homework Helper
    Gold Member

    OK. Good. Can you see how to use that?
     
  6. Aug 16, 2014 #5
    Hello, anraphy
    The particles have different masses but have equal charge.So when it's accelerated through same potential difference, they will gain equal electric energy=Vq=kinetic energy
    Vq=.5m1v12=.5m2v22
    ∴m1/m2=(v2/v1)2
    Similarly when entering in Magnetic field due to different velocities they will follow different circular path of radii ra,rb respectively.
    m1v1/ra=m2v2/rb=qB
     
    Last edited: Aug 16, 2014
  7. Aug 16, 2014 #6
    ImageUploadedByPhysics Forums1408248624.292973.jpg

    I think I got it. Thank You :)
     
  8. Aug 17, 2014 #7

    TSny

    User Avatar
    Homework Helper
    Gold Member

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Moving Charges and Magnetism Problem
Loading...