6/2 RC AC Curcuits

In todays class we explored AC RC and LRC circuits. In DC circuits, ohm's law is applied. In a AC circuit the same law applies, the only difference is that capacitors, resistors and inductors create resistance.

We began by defining a few formulas such as root mean square current, root mean square voltage,  capacitance reactance, inductive reactance, and impedance.

we began our first experiment by connecting the function generator across the resistor and capacitor with a current probe across the resistor and capacitor. 

We then started Logger Pro and connected the sensors. We measured Voltage and current. Using the stats button we got our values for maximum voltage and maximum current. We were given different frequency which we used to conduct the experiment.

Here is a close up of our values for Vmax and I max.

Here we have our second frequency.

and our second set of values for Vmax and Imax.

Using Vmax and Imax we were able to calculate experimental impedance. We then compared it to the theoretical impedance. For 10hertz, our theoretical impedance was 159.3 ohms and our experimental was 153.5 ohms with a 3.64 % error. The percentage is reasonable. For 1000 hertz, the theoretical impedance was 10.13 ohms and the experimental was 32.9 with a 224.8% error. This error was high because there must have been some inconsistency with the wiring or procedure. We also used the incorrect frequency with could've been a major factor in the high percent error. 

We also computed the phase angle using the formula above (inverse tangent *inductance reactance minus capacitance reactance divided by resistance).
In conclusion,  When frequency is low, the impedance of the capacitor is high, so most current will flow through the resistor. As the frequency increases, more current is diverted through the capacitor, and less to the rest of the circuit. Thus, the response is low pass.