**Materials** computer and internet

http://phet.colorado.edu/new/simulations/sims.php?sim=Circuit_Construction_Kit_ACDC

**Background **Tipler Chapter 30-8

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/induct.html#c1

- Construct the circuit shown to the right.
- What is the unit of the quotient of inductance and resistance? Show your work below.

- The quotient of L and R is called the time constant. Adjust the time constant of the circuit to one second. Record the value of inductor and bulb’s resistance.
- An inductor will be fully charged/discharged in a time of 4 to 5 L/R. How long will it take your LR combination to fully charge or discharge?
- Add the necessary meters and sketch the graphs of i vs t, and V
_{Resistor}vs t, on the graphs below when the inductor is charging and discharging.

Inductor is Charging | | Inductor is Discharging |

Current vs. Time | Current vs. Time | |

V_{Resistor} vs. Time | V_{Resistor} vs. Time | |

- Add the necessary meters and sketch the graphs of i vs t, and V
_{Inductor}vs t, on the graphs below when the inductor is charging and discharging.

Inductor is Charging | | Inductor is Discharging |

Current vs. Time | Current vs. Time | |

V_{Inductor} vs. Time | V_{Inductor} vs. Time | |

- When is the brightness of the bulb increasing?

- When is the brightness of the bulb decreasing?

- When does the battery supply the potential to light the bulb?

- When does the inductor supply the potential to light the bulb?

- Does the direction of charge flow change through the inductor? If yes, explain when.