QUESTIONS. With your multimeter, answer the following:
**what is the voltage across the bulb?**what is the voltage across the input to the voltage regulator?**what is the voltage across the output from the voltage regulator? **how much current is flowing through the bulb? According to the datasheet for the bulb [http://www.jameco.com/Jameco/Products/ProdDS/210008.pdf], how much current should the bulb draw? REMEMBER: measuring current with a multimeter is different than measuring voltage. You need to "break the circuit" and re-connect it through the multimeter.
=== Part 2: Series and Parallel (with bulbs)===