# Home / EEE / RL Circuits :: General Questions

### EEE :: RL Circuits

1. A 1.5 k resistor and a coil with a 2.2 k inductive reactance are in series across an 18 V ac source. The power factor is

2.  A. 564 B. 0.564 C. 6.76 D. 55.7   3. The voltages in Problem 5 are measured at a certain frequency. To make the resistor voltage less than the inductor voltage, the frequency is

4.  A. increased B. decreased C. doubled D. not a factor   5. In a series RL circuit, 12 V rms is measured across the resistor, and 14 V rms is measured across the inductor. The peak value of the source voltage is

6.  A. 18.4 V B. 26.0 V C. 2 V D. 20 V   7. To increase the current in a series RL circuit, the frequency

8.  A. should be increased B. should be decreased C. should be constant D. cannot be determined without values   9. A 470 resistor and a coil with 125 inductive reactance are in parallel. Both components are across a 15 V ac voltage source. Current through the inductor is

10.  A. 152 mA B. 32 mA C. 12 mA D. 120 mA   11. A 1.2 k resistor is in series with a 15 mH coil across a 10 kHz ac source. The magnitude of the total impedance is

12.  A. 152.6 B. 1,526 C. 1,200 D. 942    13. When the frequency is decreased, the impedance of a parallel RL circuit

14.  A. increases B. decreases C. remains constant D. is not a factor   15. A 470 resistor and a 200 mH coil are in parallel. Both components are across a 1.5 kHz ac source. The total admittance of the circuit, in polar form, is

16.  A. 12.60 –76° mS B. 12.18 76° mS C. 218 –76° mS D. 12.18 –76° mS   17. Referring to Problem 23, the reactive power is

18.  A. 10 mVAR B. 100 mVAR C. 6.76 mVAR D. 148 mVAR   19. A 12 k resistor is in series with a 90 mH coil across an 8 kHz ac source. Current flow in the circuit, expressed in polar form, is I = 0.3 0° mA. The source voltage, expressed in polar form, is

20.  A. 3.84 20.6° V B. 12.8 20.6° V C. 0.3 20.6° V D. 13.84 69.4° V   