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* Wire up a simple voltage divider using your potentiometer and a 10K resistor, conected to the 5V supply.
** Observe how the output voltage changes as you turn the knob.(measure at the point between the potentiometer and the resistor) What is the highest voltage you can get? What is the lowest?
** Now replace Replace the 10K resistor with a 1K resistor and measure how (as shown in the second diagram). Observe the voltage changes as you turn the knob, it should be different than before. What is the new lowest voltage you can get? (HINT: it should be much closer to 0V).
[[Image:Pot_divider_10k.png | 200px]]
[[Image:Pot_divider_1K.png | 200px]]
** measure the "light" resistance of your photoresistor
** measure the "dark" resistance. (cover the resistor with your hand, or try shutting it in one of the lab cabinets)
** setup Set up a voltage divider with the photoresistor and a 10K resistor. You can take your circuit from before and replace the potentiometer with the photoresistor. What range of output voltages can you get by covering or uncovering the photoelement?[[Image:Photoresistor_v_out.png| 200px]]
* Connect a transistor to control the brightness of a bulb by turning the knob of a potentiometer.
* Substitute a photoresistor in place of the potentiometer.
* Light "phobic" and light "philic" circuits with a transistor
