An RLC series circuit is driven by a sinusoidal emf at the circuit's resonant frequency.
(a) What is the phase difference between the voltages across the capacitor and inductor?
(b) At resonance, the rms current in the circuit is 120 mA. The resistance in the circuit is 20 Ω. What is the rms value of the applied emf?
(c) If the frequency of the emf is changed without changing its rms value, what happens to the rms current?