Simple AC Circuits

Contents / notes

• Explanation of AC current and voltage.
• Peak and RMS values.
• AC source connected to a resistor.
• AC source connected to a capacitor and capacitive reactance.
• AC source connected to an inductor and inductive reactance.
• R-L-C circuits.
• Vector diagrams, phase angle and power factor.
• Resistance and impedance.
• Effective voltage in R-L-C circuits.
• Resonance and resonant frequency.

Candidate objectives

• Identify AC current and DC voltage, as stated in the source.
• Differentiate between peak and RMS values of AC.
• Determine the phase difference between current and voltage.
• Interpret R-L-C circuits.
• Analyse vector diagrams.
• Calculate effective voltage, reactance and impedance.
• Recognise the conditions under which a circuit is at resonance.
• Determine the resonant frequency of an R-L-C arrangement.
• Determine instantaneous power, average power and power factor in AC circuits.