Exercise :: RC Circuits  General Questions
 RC Circuits  General Questions
 RC Circuits  True or False
16.  A resistor and a capacitor are in series across a 20 V ac source. Circuit impedance is 4.33 k. Current flow in the circuit is 


17.  For a certain load, the true power is 150 W and the reactive power is 125 VAR. The apparent power is 


18.  When the frequency of the voltage applied to a series RC circuit is increased, the phase angle 


19.  In a series RC circuit, when the frequency and the resistance are halved, the impedance 


20.  A 2 k resistor is in series with a 0.015 F capacitor across a 15 kHz ac source. What is the magnitude of the total impedance and the phase angle? 

Answer: Option C Explanation: Xc = 1/2πfC = 707 Ω Z = R  jXc = 2000  j(707) z = sqrt(R*R + Xc*Xc) = 2121 Ω Phase angle = arctangent(Xc/R) = 19.5° 