### EE 212L: Impedance and AC Power

Objective: The purpose of this lab is to experimentally determine the impedance, average power consumed, and reactive power consumed by series RL and RC circuits.

Pre-lab: Consider the series RL and RC circuits shown in Figures 1 and 2, respectively, below.

1. Given the series RL circuit shown in Figure 1 below, find
• (complex) impedance Z in rectangular form and polar form for the series combination of resistor and inductor; and
• average power P and reactive power Q absorbed by the series combination of resistor and inductor.
2. Given the series RC circuit shown in Figure 2 below, find
• (complex) impedance Z in rectangular form and polar form for the series combination of resistor and capacitor; and
• average power P and reactive power Q absorbed by the series combination of resistor and capacitor.

Laboratory Procedure:

1. Construct the circuit shown in Figure 1 on your breadboard.
Use the oscilloscope to measure the following:
• amplitude of voltage across the series combination of R and L,
• amplitude of current through the series combination of R and L, and
• time and phase difference between the voltage across and current through the series combination of R and L.
From these measurements compute the (complex) impedance, average power absorbed and reactive power absorbed for the series combination of R and L.
2. Construct the circuit shown in Figure 2 on your breadboard.
Use the oscilloscope to measure the following:
• amplitude of voltage across the series combination of R and C,
• amplitude of current through the series combination of R and C, and
• time and phase difference between the voltage across and current through the series combination of R and C.
From these measurements compute the (complex) impedance, average power absorbed and reactive power absorbed for the series combination of R and C.

© Copyright 2015 New Mexico Institute of Mining and Technology

Revised FEB2015