The document discusses motional electromotive force (emf) generated when a conductor moves through a magnetic field. It explains that as the conductor moves, a potential difference is created between its ends due to the separation of positive and negative charges. This potential difference, known as motional emf, is equal to the product of the magnetic field strength, length of the conductor, and its velocity perpendicular to the field. The document also provides examples of how motional emf causes induced currents in circuits involving moving conductors in magnetic fields.