There are some major topics covered in alternating current Class 12 notes, including The Application of AC Voltage to a Resistor, Representating AC Current, and Voltage by Rotating Vectors - Phasors, The Application of AC Voltage to an Inductor, The Application of AC Voltage to a Capacitor, The Application of AC Voltage to a Series LCR Circuit, The Application of AC Voltage to an LCR Circuit, and Power in AC Circuit: The Power Factor