Discuss the effect on the magnitude of force on a current-carrying conductor

Motor Effect

  • When a current carrying conductor passes through an external magnetic field, it experiences a force.
  • This is known as the motor effect and was discovered by Michael Faraday in 1821.
  • The direction of the 3 factors can be seen in the "Right hand palm/push rule", that is they are perpendicular to each other.

Factors that affect the magnitude of the force

  • The strength of the external magnetic field (B) is proportional to the force.
  • The magnitude of the current in the conductor (I) is proportional to the force.
  • The length of the conductor in the field is proportional($l$) to the force.
  • The angle between the conductor and the external magnetic field.
    • This is what determines the conductor's effective length, or the vertical component of the length.
      • Therefore it is given by $\sin{\theta}$ where $\theta$ is the angle to the field.
    • The force is maximum when it is perpendicular(90゜) to the magnetic field
    • The force is minimum when it is parallel (0゜) to the magnetic field.

This can be expressed mathematically as:

\begin{align} F = BIl\sin{\theta} \end{align}