How does this "Dark Meter" work? In our physics lab we used photoresistors to make a simple circuit that is light activated. It was essentially a battery hooked up to a photoresistor which was in series with an ammeter to measure the current. When the photoresistor is blocked there is low current (does the current go to zero ever? or just really close?) and when there was light a larger current would flow through. Then the next circuit was a "dark meter" it was basically the same setup except the ammeter and photoresistor were connected in parallel. It allowed more current to go through the ammeter when there was no light on the photoresistor and when there was a bright light the current through the ammeter was very low. This confused me for two reasons... 1) I thought it was improper to ever hook up an ammeter in parallel (even dangerous?) 2) how could the ammeter be affected by the photoresistor? They are in parallel so no matter what the resistance is through the photoresistor, the current through the ammeter would be constant right??