Summary
● Ohm’s law applies to AC circuits, just as it does to DC circuits.
● The AC current lags the voltage by 90° in an inductor (ELI).
● The AC current leads the voltage by 90° in a capacitor (ICE).
● Vector representation allows the use of trigono- metric functions to determine voltage or current when the phase angle is known.
● The combined effect of resistance and inductance or capacitance is called impedance.
● Apparent power is obtained by multiplying the source voltage and current with units of volt-amperes.
● The ratio of true power to apparent power in volts- amperes is called the power factor.
● The power factor is very important in the consideration of heavy industrial power distribution.
● Resonance circuits make it possible for a circuit to tune a station to a particular frequency.
● Resonance is desired for radio frequency in tuning circuits.