Learning Exercise

Voltage Divider

This was used as an interactive discussion/lab exercise to replace a similar paper and pencil exercise. Students were strongly engaged with the exercise.
Course: Physics 2 for Scientists and Engineers
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The Ohm Zone's Shockwave application that allows you to build your own DC circuits and measure the voltages and... see more

Exercise


  1. Measure the value of the resistance for the four different types of resistors in the simulation. Note: The ammeter (measures current) and volt meter (measures voltage difference) are the two small circles in the lower left corner of the simulation.

  2. Build two circuits (shown on the worksheet). The first is a voltage divider with a 10 ohm resistor and a 20 ohm resistor, and the output measured over the 20 ohm resistor. Next put a 200 ohm load on the output (20 ohm resistor). Since you only have one battery, you can only run one circuit at a time. What are the voltage drops across each of the resistors in these two circuits? Explain the relative magnitudes of each of the voltage drops.

  3. If, in the second circuit, the ?Load? is reduced to 20 ohms, calculate the voltage drops across each of the resistors, then use the simulation to measure them. Explain the changes from the voltages found in question 2 above.

  4. Just for fun: Using the 8 resistors in the circuit simulator, how many different ways can you make a circuit with a total resistance of 50 ohms? Use the circuit simulator to test your answers.

Technical Notes

This exercise was run in a computer lab with students working on individual machines but discussing their results in small groups. The instructor was present.

Requirements

Understanding of Ohm's law and some DC circuits.

Topics

DC Circuits, Ohm's Law

Learning Objectives

Create circuits that can be used to measure physical properties of DC circuits and resistors.