Category Archives: Quantum Effects

Vibrating Soap Film

Demo: MP-A-VS
Pira Index: 7A 50.30

 Lab Equipment  Directions
  1.  Pasco mechanical vibrator
  2. strobe light
  3. Pasco function generator
  4. Plexiglas circular tray
  5. Hoop with 3 wires and banana plug
  6. Soap bubble solution
  7. 2 BB leads
  8. lab stand
  9. 90 degree clamp
  10. short metal rod
  1.  Set up apparatus as shown.
  2. Pour soup solution into tray. Lower rod and vibrator until the hoop is in the soap solution.
  3. Raise rod back up and make sure there is a soap bubble across hoop. With amplitude set to low, turn on the function generator.
  4. Vary the frequency and look for a standing wave to develop across the bubble. Set the strobe to match the frequency to make the pattern appear to stand still.
Note – use only for small groups


Vibrating Circular Wire, OHP

Demo: MP-A-VC
Pira Index: 7A 50.40

 Lab Equipment  Directions
  1.  Pasco function generator
  2. Pasco mechanical vibrator
  3. circular wire
  4. 2 BB leads
  5. Overhead projector
  1.  Connect as shown. Position the vibrator so that the circular wire rests on the overhead projector table and can be seen completely.
  2. Set the function generator amplitude to not more than half scale before turning on.
  3. Adjust the generator frequency scale until you find a 3 node resonance. (approx. 20 Hz)
  4. Try other frequencies to obtain various resonance. (Try 60, 100, and 140 Hz)


Photo-Electric Effect

Demo: MP-A-PE
Pira Index: 7A 10.10

 Lab Equipment  Directions
  1.  Special black covered UV lamp
  2. Electroscope
  3. Zinc Plate
  4. Steel wool (fine)
  5. Special UV blocking plastic
  6. Lucite and PVC rod
  7. paper towel
  1.  Clean the zinc plate very well with steel wool. Then put the plate into the top of the electroscope as shown.
  2. Place the electroscope in front of the UV lamp.
  3. Rub the PVC rod with the paper towel and charge electroscope by touching the rod to the plate.
  4. Depress the switch on the UV lamp. The electroscope will discharge.
  5. Repeat with the lucite end of the rod (positive charge). You see no discharge.
  6. Blocking plastic can be placed between the electroscope and the light to block UV. There will be no discharge with either charge on it.


Optical Communication

Demo: MP-A-OC
Pira Index: 7A 10.00

 Lab Equipment  Directions
  1.  Radio or tape player with tape
  2. LED or plexiglass plate
  3. thermopile on plexiglass plate
  4. amplifier speaker box
  5. remote
  6. lumirod
  7. 9V battery
  1.  Connect equipment as shown. Preset radio on a station or put audio tape in tape player.
  2. Align the LED and photocell as shown.
  3. Listen for sound on amplifier speaker.
  4. Move the thermopile back and forth and hear the signal come and go.
  1. Hold the speaker and thermopile in line with a remote, press a button, and hear its signal.
  2. Use the lumirod to carry the light signal from the LED to the thermopile.


Fuel Cell

Demo: MP-A-FC
Pira Index: 7A 10.90

video link: Fuel Cell

 Lab Equipment  Directions
  1.  Fuel cell
  2. Deionized water
  3. Blue lamp
Remove top cylinders. Fill lower cylinders with DI water to just below upper hoses. Close clamps on lower fuel cell hoses. With fingers, pinch hose leading from fuel cell into lower cylinder as you fill each side completely with water. Replace upper cylinders (some water will overflow).
Practice is strongly recommended.
  1.  There should be no large air bubbles in tanks or hoses between cylinders and solar cell.
  2. Illuminate solar cell, allowing the solar cell to electrolyze water until at least 1.5 cm of O2 has built up (20-30 minutes).
  3. Open a hose clamp until gas pushes all water out of upper hose and into fuel cell. Repeat for other side. (Hose may need to be bled to start process-careful not to lose gas).
  4. The fan should begin to turn as the fuel cell recombines the gases, releasing energy.


Electron Diffraction

Demo: MP-A-ED
Pira Index: 7A 60.10

 Lab Equipment  Directions
  1.  TeleAtomic electron diffraction bulb and holder
  2. TeleAtomic kV power unit
  3. 2 AB leads and 2 BB leads
  1.  Connect the apparatus to the power supply as shown.
  2. After the tube warms up, two prominent rings about a central spot are observed.