EMF Induction in Rotating Loop

Voltage Induction in a Rotating Loop

• A voltage is induced in a wire loop when the rotor of a machine is rotated.

Magnetic Field and Rotor Surface

• The magnetic field is constant and perpendicular to the rotor surface everywhere under the pole faces.
• The magnetic field rapidly falls to zero beyond the edges of the poles.

Voltage in Each Segment of the Loop

• Segment ab:
  • Velocity of the wire is tangential to the path of rotation.
  • Magnetic field B points out perpendicular to the rotor surface.
  • v × B points into the page, resulting in a positive voltage.
  • e ba = (v × B)l, where v is velocity, B is magnetic field, and l is length.
• Segment bc:
  • v × B is either into or out of the page, while length l is in the plane of the page.
  • v × B is perpendicular to l, resulting in zero voltage.
  • e cb = 0
• Segment cd:
  • Velocity of the wire is tangential to the path of rotation.
  • Magnetic field B points in perpendicular to the rotor surface.
  • v × B points out of the page, resulting in a voltage.
  • e dc = (v × B)l, where v is velocity, B is magnetic field, and l is length.

Total Voltage

• The total voltage etot is the sum of the voltages in each segment of the loop.

This quiz explores the concept of electromagnetic induction in a rotating loop, where a voltage is induced in the wire loop when the rotor is rotated. The quiz delves into the factors affecting the magnitude and shape of the voltage, including the magnetic field and the loop's orientation.