An ac voltage source is connected in series with a1.4-?F capacitor and a 690-? resistor. Using a digital ac voltmeter, the amplitude of the voltage source is measured to be 4.0?V rms, while the voltages across the resistor and across the capacitor are found to be3.0?V rms and 2.7?V rms, respectively.
Determine the frequency of the ac voltage source.