Please answer the following questions in writing before coming to lab 9. You will be handing them in and they will make up part of your lab 9 grade.

1. What are the differences between these two physical quantities: electric current I, voltage Delta V?
2. Draw a complete circuit with a battery, switch, and an incandescent light bulb that results in the bulb lighting up. Explain the mechanism behind the emission of light from an incandescent bulb.
3. Draw a complete circuit with a battery, switch and a commercial resistor. Describe an experiment that would let you create a function I(Delta V) for the resistor? That is, a mathematical function describing how the current through the resistor depends on the voltage across it. Based on your understanding of resistors, sketch a graph of what this function will look like. How would the graph be different if the resistance of the resistor were greater? Explain.
4. What physical quantities do you need to measure to determine the electric power dissipated by a particular circuit element? What mathematical procedure will you use?
5. What are the differences between the mechanisms of electric conductivity in metals vs. semiconductors?