# Energy Change in Circuits

 Materials: None Time Allotment: 2 Class Days

### Overview:

This makeup lab is unique from most others in that it does not actually involve a laboratory exercise. Rather, this makeup lab involves the completion of a writing assignment which demonstrates your understanding of the energy transformations which occur in circuits.

### The Assignment:

Our Current Electricity unit has focused (in part) upon energy transformations which occur in a circuit. We have discussed the role of the battery and the role of resistive elements in a circuit with regards to the energy supplied and expended. Write several paragraphs in which you

• identify the requirements for the establishment of an electric circuit and use two simple diagrams to illustrate an example and non-example of a battery, wire and light bulb arrangement which would and would not result in a current; incorporate the diagram into your writing.
• discuss the role of the battery in an electric circuit, explaining its importance to the flow of charge.
• identify and elaborate upon several (at least three) common misconceptions which people have concerning the battery, charge flow, and electric circuits.
• construct a circuit diagram (refer to circuit symbols given in the textbook) of a simple series circuit with at least three resistors; on the diagram, neatly do the following:
1. use an unbroken arrow to show the direction of conventional current.
2. mark and label (using letters A, B, C, D, etc.) at least six individual points on the circuit (excluding points present on the actual resistors.
3. label a voltage for the battery and resistance values for each individual resistor (do not use the same value).
• discuss the energy changes which occur to a single coulomb of charge as it makes a complete cycle through the entire circuit diagrammed in the step above; be specific in your discussion by identifying the specific points on the circuit which you have already labeled; use both qualitative terms (a gain or a loss in energy) and quantitative terms (e.g., 6 Joules).
• compute and clearly state the current flowing through the circuit as well as through each individual resistor; finally compute and clearly state the voltage drop across each individual resistor.

In your writing, use complete sentences and the language of physics. The assignment should be less than 1 page long and no more than 3 pages long.