Resistors in an electrical circuit are made of graphite and resin.  In this activity students will model resistors in an electrical circuit using graphite art pencils and graph paper.  Students will draw lines of graphite on the graph paper and measure the electrical resistance with a digital volt ohm meter (VOM). Students will discover the relationship between the length of the lines and the electrical resistance and the width of the lines and the electrical resistance.  These relationships are the basis for the equations that the students will use to calculate total resistance in a series and parallel circuit.

In this lesson students will build a speaker coil.  When they hold the coil in their teeth and plug it into a sound source, they will hear the music in their head through bone conduction. Students will then draw a diagram of a speaker with an explaination to demonstrate their new found knowledge.

In this lesson students will learn about thermoelectric devices (TED) and plot Voltage Vs Temperature graphs for the devices.  Thermoelectric devices work two ways.  When a voltage is applied to them one side gets hot and the other side cools.  Some travel coolers work this way.  The other mode works the opposite way. When the device is subjected to a temperature difference, it produces a voltage.  It is like a solar cell that responds to heat.