A video lesson on Magnets & Electromagnets (11m).
Science in Action – Electricity & Magnetism – a 20m video; Scientific Eye – Magnetism – a 19m 24s video; Scientific Eye – Electricity & Magnetism (20m).
KS3 Bitesize – Electricity & Magnetism – a foundation-level video covering Electrical Current in Circuits, Bar Magnets & Magnetic Fields and then Electromagnets & Electromagnets – a higher-level 5m 40s video.