Link to Ohm's law lesson plan.
Link to Ohm's law training video.
*Note that this experiment/demonstration activity requires some specialized equipment. A teacher would need batteries, wire or cables, ideally a few resistors, and some type of ammeter (measures electric current). If you do not have access to such equipment, especially an ammeter, if you have small light bulbs or LEDs, one can get a measure of electric current by the brightness of the bulbs.
Ohm's law is a basic rule for resistor circuits. One can make a simple circuit just by connecting a wire to some device that has resistance, and then touching the wires to the two terminals of a battery. Electricity will flow through the device, which should then begin producing heat. If you have light bulbs, those could serve as resistors, and the brightness of the light will indicate the amount of electric current flowing through the resistance.
This experiment has students do two procedures. The first has a fixed resistance, which could be a resistor or a light bulb, and then vary the voltage. One would need multiple batteries, so that you could double, triple, and quadruple the voltage if you had two, three and four batteries connected together in series. The light bulb should increase in brightness each time a battery is added, since the current increases linearly with the voltage.
The second procedure would use a fixed voltage, say just one battery every time, but with a different resistance each time to see how that affects the current. One could add light bulbs in series each time, and for every light bulb added, the brightness in each bulb should decrease, since increasing the resistance will lower the current. If you happen to have an ammeter, a direct measure of amperes of current could be made and graphed.
The results of these two experiments allows Ohm's law to come out:
electric current = voltage/resistance, or I = V/R
Have fun with simple circuits and Ohm's law.
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