Phet Electricity & Magnetism LR Lab

AP-C

Electricity & Magnetism Induction LR Lab

Name ____________________ Teacher __________________ Period _____

Purpose

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

Directions

1. Construct the circuit shown to the right.

2. What is the unit of the quotient of inductance and resistance? Show your work below.

3. 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.

4. 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?

5. Add the necessary meters and sketch the graphs of i vs t, and VResistor 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
VResistor vs. Time		VResistor vs. Time

6. Add the necessary meters and sketch the graphs of i vs t, and VInductor 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
VInductor vs. Time		VInductor vs. Time

7. When is the brightness of the bulb increasing?

8. When is the brightness of the bulb decreasing?

9. When does the battery supply the potential to light the bulb?

10. When does the inductor supply the potential to light the bulb?

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

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L =

R =

time =