Impedance

Introduction: In this lab, we are going to apply voltage with different frequency to RR, RL, and RC circuit to measure current through each circuit.

                 First we calculated expected current in each circuit when amplitude of 2V and 5k frequency for supply voltage.

Expected current in each circuit.

In the following graphs, channel 1 (yellow curve) is voltage across 47-ohm resistor, channel 2(Cyan curve) is either 100-ohm resistor, capacitor, or inductor depends on which circuit, and Channel 3(Orange curve) is current through circuit.

1k frequency, 100-ohm Resistor

5k frequency, 100-ohm Resistor

10k frequency, 100-ohm resistor

With resistor component, voltages and currents are in phase and magnitudes did not change, but periods changed in different frequencies.

1k, Inductor Gain=0.1305, Phase= 278.1°

5k, Inductor, Gain=0.5381, Phase=27.365°

10k, Inductor, Gain= 0.7938, Phase=272.34

1k, Capacitor, Gain=1 Phase=89.424°

5k, Capacitor, Gain=1,Phase= 90.77°

10k, Capacitor, Gain=1, Phase= 86.76°

Summary: In all experiments, current is always in phase with voltage across 47-ohm resistor.
When we connected a resistor in series with circuit, the gain, amplitude did not change and 3 curves were all in phase. When circuit connected with an inductor, the gain increased with frequency and have certain phases. When circuit is connected with a capacitor, the gain was always one and also current increased as frequency increased.