Testable Question: How does current depend on the voltage and resistance of devices in an electric circuit? Use this Phet to change the variables to determine the effects of voltage and resistance in BOTH a series and a parallel circuit. Experiment 1: How does current depend on increasing voltage in a series circuit (begin with 1.5 V)? Experiment 2: How does current depend on increasing resistance in a series circuit? Experiment 3: How does current depend on increasing voltage in a parallel circuit (begin with 1.5 V)? Experiment 4: How does current depend on increasing resistance in a parallel circuit