Describe qualitatively and quantitatively the force between long parallel current-carrying conductors

Motors and Generators > 1. Motors and Magnetic Forces >

Describe qualitatively and quantitatively the force between long parallel current-carrying conductors:

  • Wire with current gives magnetic field which exerts a force upon objects
  • 2 parallel wires with a current produce magnetic fields that affect each other
    • Same direction: fields attract and combine
    • Opposite: Fields repel each other
  • Use right hand grip (thumb – current, fingers – magnetic field) to determine direction and whether there will be attraction/repulsion
  • Magnitude can be found with:
  • In the above equation:
    • F = force between conductors
    • I1 and I2 are the currents passing through the conductors
    • d is the distance between the conductors.
    • l is the length of the conductors
    • k is a constant (2x 10-7)
  • Force is increased with longer wires and less distance between them
  • In one wire: