Voltage, current, power, and resistance

In physical science the course moves at a topic a week. Week twelve is electricity. This term the prior week had a Thursday holiday. A week without a Thursday lab is a week in which I usually run videos on topics that are better handled by videos. I ran videos on the nature of time and when time may have begun, I also ran a series of videos on climate change.

Trisden and Twain

The climate change videos provide a natural transition to the Micronesian Seminar's video "Power comes in many forms." In that video the concepts of head and flow are introduced in the context of micro-hydroelectric power generation units.


I then build on the head as akin to voltage and flow as akin to current. Head is a measure of pressure, and for a beginner thinking of voltage as a pressure is a useful starting place.

Maxon, Kenoma, and Tania explore conductors and non-conductors

Wednesday is a traditional lecture on voltage, current, power, resistance, and Ohm's law. This includes having the students run calculations on various electrical devices. This term I did not bring in a PUC power slip, when time permits I like to explain how the power consumption of an appliance can be translated to a cost in terms of cashpower. I also did not make the trip to the solar panel output as the monitor for that system remains down.

Cells in series

The Wednesday lecture then segues nicely into a simple three part electrical laboratory: batteries and bulbs, conducting and non-conducting materials, and an Ohm's law demonstrator experiment. In the morning class Kenoma opted to hook batteries up in series. I have yet to see the data from this setup. In the afternoon I assisted and set the cells up in series which generates the classic Ohm's law relationship. I used Desmos to plot the points and show that the data was linear, then Google Sheets to obtain the slope.

Friday was a holiday, the week ended on the laboratory.

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