A 6.8 k resistor, a 7 mH coil, and a 0.02 F capacitor are in parallel across a 17 kHz ac source. The coil's internal resistance, R_{W}, is 30 . The equivalent parallel resistance, R_{p}(eq), is

A 200 resistor, a coil with 30 of reactance, and a capacitor of unknown reactance are in series across an ac source. The circuit is at resonance. Circuit impedance