Electrical Resistance and Capacitance of Oreos

Contributors: Kyle Appleman, Dale Salmon, & Benjamin DeJonge

 

EXPERIMENT:

  • To determine the resistance of an Oreo, and (if applicable) determine the capacitance of an Oreo cookie.

MATERIALS:

  • Capacitance meter
  • Metal Washers
  • Voltmeter
  • Ammeter
  • Wires
  • A Large amount of Oreo Cookies
  • Source of potential difference

PROCEDURE:

  1. Part 1 - Checking for conductivity.
    1. Clip two leads across the biscuit of the Oreo.
    2. Apply varying levels of voltage across the biscuit and record the current flowing.
    3. Repeat the above steps, this time using the creme portion of the Oreo.
    4. A 2cm thick "bar" of creme can be used to check the for current flow using high voltage if necessary.
  2. Part 2 - Measuring the capacitance (of the creme)
    1. Remove cream from Oreo and place onto metal washer.
    2. Place another washer on top of the creme and "sandwich" the cream.
    3. Connect wires to each washer.
    4. Connect battery to wires and charge capacitor.
    5. Disconnect battery
    6. Clip capacitance meter to wires on washers and measure capacitance.

DATA:

  • There is no data to record necessarily.

RESULTS PART 1:

  • DC voltages of 1.5V, 3V, 4.5V, 6V, 7.5V, 9V, 12V, 15V, 18V, 20V, and 24V were applied across first the biscuit and then the creme.
    • No measurable current was detected.
  • AC voltages of 2V, 4V, 6V, 8V, 10V, 12V, 14V, 16V, 18V, 20V, 22V, and 24V were applied across first the biscuit and then the creme.
    • No measurable current was detected.
  • High AC voltages of 120V and 30,000V were applied across a 12cm bar of Oreo creme. The purpose of using a long bar of creme was to prevent excess current flowing.
    • No measurable current was detected.
    • It was noted at 30,000V there was a "hissing" heard as the two leads neared one another (3cm apart). This was due to the breaking-down of air between the leads and not¬†due to the conductivity of the creme itself (so assumed).

RESULTS PART 2:

  • After constructing a simple parallel-plate style capacitor there was a 3.2pF measured capacitance.
  • Connecting 10 capacitors in parallel (for largest total capacitance) resulted in a 0F measured capacitance.
  • Connecting 10 capacitors in series (for smallest total capacitance) resulted in a 0F measured capacitance.
  • The measured initial 3.2pF across a single creme-capacitor may be due to the delicate nature of the capacitor meter: repeated trials resulted in values ranging from -5.7pF to 5.2pF. This suggests that the meter has trouble being properly "zeroed" in this extremely small farad range.
  • Further testing was done charging the bank of capacitors and attempting to measure to voltage drop across a resistor in series with the bank.
    • The recording software was unable to measure any initial voltage across the "charged" capacitor bank. This suggests that the capacitor doesn't hold a charge well, or perhaps too small a charge to be measured with the provided hardware and tools.

POSSIBLE APPLICATIONS:

  • Oreos could make a good material to make insulating stands out of for electrical experiments.
  • Static sensitive computer components could be shipped between Oreos, this would also serve as an environmentally friendly packaging material!

EXTERNAL LINKS:

 DISCLAIMER: The views and opinions expressed herein are in no way affiliated with the Albion Central School District or Nabisco in any way.