This presentation reviews the big ideas in electromagnetism. 
These describe how charges make electric and magnetic fields and how these fields exert forces on charges. 
We can summarise these big ideas as follows:
Charges create electric fields and electric fields exert forces on charges
Moving charges make magnetic fields and magnetic fields exert forces on moving charges.
Finally, changing magnetic fields create electric fields and changing electric fields create magnetic fields. 
Each of these sections reviews how these big ideas feature in your year 11 and year 12 syllabus.
 Finally, the last section examines the significance of reference frames and energy conservation in electromagnetism, 
and how this relate to Lenz’s law.
