Go to https://phet.colorado.edu/en/simulation/circuit-construction-kit-dc and click on Download and then Run. Drag circuit elements from the carousel on the left into the play area. Connect them together by overlaying the dashed circles. Clicking on the connections allows you to cut them. Delete circuit elements by clicking on them and then selecting the trash can. You are encouraged to play freelyin a simulation you can't hurt anything (neither the equipment nor you!). Activity 4 | Resistance (Adapted from PhET Colorado2) Resistance R impedes the movement of charges in the circuit. In the carousel you have resistors whose job is to accomplish this. Resistors dissipate thermal energy when there is current in them. The bulbs are merely resistors that get hot enough to glow; for this reason, bulbs can function as visible current indicators if you don't have an ammeter (although their own resistance changes the current in the circuit). The SI unit of resistance is the ohm with symbol .

a. Guess/predict a rule for the equivalent resistance of a given set of resistors in series.

b. Check your predicted rule by putting two or three resistors in series with a bulb and see what that does to the brightness of the bulb. Verify with an ammeter the effect of adding resistors in series. Doubly verify your rule by changing the resistance of one or more of the resistors. Triply verify by changing the resistance of the light bulbit is just a resistor that glows.

c. What does the ammeter say about the current in all the resistors and the bulb in series?

d. What does the voltmeter say about the voltage across each different resistor in series?