GEP 374b

Ohm’s Law Planning Day

Safety Concerns

In this lab, devices will be dissipating heat and components may get hot enough to cause skin burns. Please pay attention to the amount of power you are supplying by monitoring the voltage and current from your power supply.

Remember that Ohm’s law doesn’t ask before acting.

Materials

  • DC power supply
  • Test leads
  • Multimeter

Planning

  • Devise a plan to measure the electrical behavior of something and determine if it behaves according to Ohm’s Law.
    • What tools would you use?
    • How would you connect these tools?
    • What data would you collect?
    • How would you tabulate or plot your data?

Ohm’s Law Data Collection Day

Data Collection

  • Group up into teams
  • Revisit your data collection plan
  • Choose a device to measure
  • Take data and intepret
  • We will share results in class

Ohm’s Law Data Analysis Day

Analysis Plan

IV Curve and Resistance:

  • Review data in lab book
  • Create well-labeled graph
  • Estimate slope of your graph and show how you calculated it
  • Compare your calculated slope to the value of your resistor

Power Delivered:

  • Calculate the expected power delivered from the current and voltage at each point.
  • Sketch the power delivered versus the applied voltage
  • Compare your expected power to the power on the power supply.

Light Bulb:

  • Comment on how the light bulb behaved differently from the resistor.

Exercises

1 Electricity Fundamentals Notes

Read notes on electricity fundamentals and write in your own words.

  • What does Ohm’s Law (V=IR) predict?
  • What does the equation (P=IV) tell us?

2 Proposed Measurement Procedure

Write up a procedure that you will follow to set up an experiment, collect data, analyze the data, and interpret the result.

3 Data and Graph

Upload a word processor document (Word, Google, etc) with your results.

  • include a table of your data (either digitally or scanning your notes)
  • include a graph sketch showing how you determined the resistance (by scanning your notes)

4 Ohm’s Law Reflection

Please write a short essay (50 words) covering the following questions.

  • What new knowledge did you gain?
  • What new skills did you develop?
  • What could you take from this activity and apply to your career interests?