After this lesson, you should be able to:

• Explain the advantages of alternating current
• Write expressions for current and voltage in an AC circuit
• Define the rms values for current and voltage and explain their usage
• Know that the average power is given by P_av = I_rms V_rms = ½ I_max V_max
• Draw graphs of voltage versus time and current versus time for an AC circuit
• Solve problems using the concepts P_av, I_rms and V_rms