User:Darrell Bonn/Notebook/307L Lab book/lab 5 Millikan

Procedure

Equipment setup

1. Measuring the thickness of the plastic between the plates. D for capacitor: 7.75mm, 7.76 on other side
2. Cleaned capacitor with dry paper towel, took care to remove any particles
3. Placed the focusing wire in place, connected light and focused on the wire
4. Adjusted the light to best illuminate the wire exactly as explained in manual. Removed the focusing wire.
5. There are 5 small divisions per large division in the viewer grid
6. Attached 500 volt power supply.

Measurements Time measurements are between two major lines Initial Trials – We took a bit of time to simply play with the tools to be sure we understood what we were doing. Barometric pressure: 30.41 in / 1029.7 hPa (from http://www.wunderground.com/US/NM/Albuquerque.html) Measured 500.8 V on the capacitor Temperature within the chamber 26C Added droplets with a single squeeze of the atomizer. Immediately saw drops within the viewer. Picked a small, slow moving one and timed it. Picked a drop, Setting top plate positive, it went up Seconds: 6.3 4.33s up, 410s up, 4.27 up, 17.56 down without, 19.24 down without ..lost him 18.17 down without, 19.46 down without, 13.12 up, 17.46 up, 11.27 up, 12.55 up, 11.58 up, 19.86 down without Drop 2 Up under positive charge on top plate: 8.62, 7.36, 7.55 Down with plates grounded: 23.08, 26.5, 26.98 Down with negative charge on top plate:

Measured temperature: 27C

Drop 3

Up under positive charge on top plate: 2.24s, 2.56s, 2.37s Down with plates grounded: 7.17s, 6.46s, 6.81s Down with negative charge on top plate: