ELEC 101
Prof. Rich Kozick
January 29, 1998

Laboratory 2 Kirchhoff's Laws, Resistors, and the Votage Divider

In this lab session, you will have the opportunity to work through electronic lessons on Kirchhoff's laws and resistance. You will also set up some simple circuits and take measurements. Although the electronic lessons repeat the material from class and the text, seeing the concepts in a different form should help increase your understanding.

1. If you did not have your power supply for Lab 1, please measure the voltage differences between the various wires on your power supply. Determine which wires correspond to +12 V, -12 V, +5 V, and Ground. Record the results in your lab notebook for future reference.

2. Perform the electronic lessons listed below using the Exploring Electrical Engineering program on the PC at your lab bench. Record results in your lab notebook as follows. If the lesson asks you a question based on the reading in the lesson, then nothing needs to be recorded in your notebook. (But feel free to take notes if you would like.) For all of the experimental activities in which you take a measurement or set up a circuit, briefly describe the activity in your notebook and record your results.

The following lessons are under the Basic Concepts menu. In each lesson, please answer all of the questions, do all of the activities, and show your results to the lab instructor or lab assistant when requested in the lesson.

• Please finish the lesson on Measuring Voltage that you began last week. Set up the circuits that are requested and make the requested measurements.

• Do the lesson on Measuring Resistance. You can skip the exercise that uses the pencil - that will be done in a later lesson.

• Do the lessons on Resistors (there are three lessons) and Sources (one lesson on ideal sources). These are located under the Elements menu item.

• Do the lessons on Kirchhoff's Current Law and Kirchhoff's Voltage Law. Do the quizzes at the end, and show the instructor your results.

3. Set up the "voltage divider" circuit shown below using your protoboard and power supply. Choose two different values for the resistors, and choose the resistors so that the current drawn from the power supply is no greater than approximately 10 mA.

Measure the voltage drop across each resistor, and compare your measured value with the value computed by the formulas.

[CIRCUIT DIAGRAM AND FORMULAS ARE NOT AVAILABLE IN HTML DOCUMENT.]