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Basic Switches Virtual Lab

This is a version of the Basic Switches Lab lab conducted virtually, using the simulation below. The goal is to learn how to properly connect a switch in a circuit. I recommend you select "intro" mode, although you can use either "intro" mode or "lab" mode.

Simulation provided by PHET interactive simulations at the University of Colorado at Boulder

Virtual Materials

Procedure and Questions

Note: All of the switches in the circuit diagrams for this lab are being drawn as open switch. This is because it is much easier to see them. Obviously, the point is to open and close the switch after you build it to see how it works.

  1. Start with a circuit containing just a light bulb and a battery:

    Then, add a switch in series with the light bulb, like this:
    Move the switch up and down. (by clicking on it) Does it work?
  2. What happens to the moving electrons in the circuit when the switch is open? Do they move partially or stop moving entirely?
  3. Now try rewiring your circuit so that the switch is connected to the light bulb in parallel:
    Try flipping the switch on and off. It should still work, because when you switch it the light bulb changes between bright and dim.....but you will notice something a little strange. What?
  4. I like to call this a "reverse switch." Why does that name fit?
  5. When the switch is on, what happens to the battery. Why? You can look back at the previous lab on short circuits for guidance.
  6. Using information from the previous lab on short circuits, answer these questions: Why is the light bulb off when the switch is on? Why is the light bulb on when the battery is off?
  7. If you want a switch to properly control a light bulb, do yo want to connect it in series or parallel with the light bulb? Give two reasons why: one reason that deals with safety and another with making your circuit easy to understand.