23 - Apparent Power and Power Factor

INTRO: Today we continued our lecture on AC power by moving onto the topics of apparent power and power factor. Due to the non-constant nature of AC current, there are several power measurements used for an AC system. We will add these two new quantities to the list.


Pictured at the bottom of the page in the picture are the definitions for apparent power and the power factor. The apparent power is the combination of true and reactive power in a circuit. The power factor is the ratio of the average power to the apparent power.


Below is a visual representation of the apparent power. It is the combination of the reactive and real power in a circuit.




LAB: Apparent Power and Power Factor
In this lab we will use work around the apparent power and power factor when working with a circuit. Mainly we will deal with power transmissions to our AC circuit and also deal with the delivery efficiency of the power.


Below is a schematic we will build during this lab. It is a fairly simple lab, however it will be perfect for what we need.


Below is the circuit we built. We used a 10, 47, and 100 ohm resistor. When we measured the actual resistance of the resistors with our multi-meter they were relatively close to the given values.


Below is the table of several values we found when performing adjustments to our circuit. We found our Vrms, as well as thevenin equivalent resistence, inductance, and several other values. AS the table shows, we performed operations with our circuit with the three different resistors.


Below is our graph when we have the 10 ohm resistor. We find the magnitudes and phase angles by the graph quantities.


Below is our graph when we have the 47 ohm resistor. We find the magnitudes and phase angles by the graph quantities.


Below is our graph when we have the 100 ohm resistor. We find the magnitudes and phase angles by the graph quantities.