### Electricity laboratory 12

Laboratory twelve in SC 130 Physical Science focused on the simplest of electrical circuits, electrical conductivity, and Ohm's law.

Cuteleen has lit a single bulb using a wire, a 1.5 volt cell, and a flashlight bulb. This term only a couple of students reported having done this exercise, and both noted that they did not do this activity in class but rather at home playing with a flash light bulb.

For me this captures in a single anecdote the sad state of hands-on science education in the elementary and secondary schools. Term after term only two to three students will have had any encounter with this activity that is sometimes known as "batteries and bulbs." Yet this is an easy to do, basic introduction to electrical circuits.

The students invariably create a short circuit at some point, which leads to a really hot wire. This provides a good opportunity to cover the potential fire danger of short circuits.

This electrical laboratory also explores Ohm's law. Jessica Salvador and Jessica Herry take data as Joyceleen activates the three bulb circuit. Rico and Iniki look on. The result of the gathered data will be an V = iR xy scattergraph where the linear regression has a slope of R. The complication with the rig is that resistance varies with bulb temperature. I prefer bulbs to resistors, however, because the students can see the bulb is lighting up. Otherwise there would be nothing to see but the mysterious deflection of the ammeter and voltmeter.

The third portion of this laboratory is the exploration of which materials conduct electricity. This ties back to the laboratory on heat conduction. Palikkun checks for connectivity while Hanna records the data.

Melinda works on getting the bulb to light - a new experience for her.