DL-Circuits
Demo - Ohm's Law - I connect a light bulb to a power supply in series with a slide wire rheostat. I show the effect of more and less Voltage (Voltage like pressure) and the effect of more and less resistance.
Demo - Three Light Bulbs - Given the circuit diagram, the students predict the effect of turning on light bulb 3 on the brightness of light bulb 1 and 2. I have them vote and raise their hand.
Lab - stuff
Lab - Resistance of a wire. Students gather Current vs Voltage data for a piece of NiChrome wire. They make a graph with generous error bars, and put a linear model through it. Then they estimate the uncertainty of the slope by putting min and max slope lines through the data. This data is Ohmic - constant slope, 0 y intercept.
or like this: https://sites.google.com/a/ttsd.k12.or.us/tuhsphysics/home/htp-ib-physics/graphing-prelab
Lab - Light Bulb and Diode. Students gather Current vs Voltage data for a light bulb just as it is getting hot, and a diode just as it is letting current flow. These graphs are very non-ohmic. The light bulb is a beautiful downwardly concave graph of I vs V. The Diode is nominally linear, but has a huge negative y intercept.
I have the students use best fit lines to find the differential resistance on the graphs.
Lab - Internal Resistance of a Battery. Students gather Voltage vs Current data for a battery under various loads (currents). As the current increases, the terminal voltage of the battery decreases, and they use this to determine the internal resistance of the battery.
Lab - I do this as a station lab.
Oscilloscope Lab Part 1 - and old fashioned CRT Oscilloscope. Students look at the output of a transformer (about 6 V output) and determine the peak voltage of the waveform, and the period. From this they calculate the RMS voltage, and the Frequency of the waveform (about 60 Hz)
Oscilloscope Lab Part 2 - A $14k Tektronix prototype donated by parent Devin Bingham. Students analyze the input and the output of a full wave bridge rectifier. See the handout. It's pretty cool.