Millikan Oil Drop Lab

Here is the lab handout:   Lab-MillikanOilDrop.pdf  .:.   Murray's Spreadsheet Period 4 .:. Period 5

The overview of the experiment:

To Install the Simulation on a PC with DOS box: (2021 on -skip this step)

• 1. Scroll to the bottom of this page, and click the Download button next to the file MILLIKAN.zip.

  2. Open that file (If you are using Chrome, just click on it in the Browser tray)  When you do you will see a folder containing a folder called MILLIKAN

  3. Type Windows-E to open a new Windows Explorer window.  Put the new window side by side with the MILLIKAN window

  4. In the Explorer window you just opened, click "This PC" in the left hand pane

  5. Drag the folder named "MILLIKAN" to the c: drive on the PC

  6. You are done

How to run the simulation:

Run the Millikan program Starting the lab (Video does not do the "cycles 4000" command)

Run DOS Box by double clicking the desktop icon, and type these commands:  (followed by enter or return ; - )

cycles 4000
mount c c:\millikan
c:
millikan

Typing alt-Enter will make the simulation go full screen if you like

When you quit you can either type exit at the prompt, or close the window

Data gathering:

Here is the basic flowchart:

1. Get a new drop

2. Determine its size. (Drop it 3x - write down drop divisions...)

3. Zap/Suspend until:

A. You reach 25 unique points.  record negative voltages as positive.  (i.e. -89 V and +89 V are the same point, and are not unique)

B. Or if you lose the drop, go to 1

C. Or if the random number generator won't give you any more values, go to 1

Get a new drop

1. Get a new drop (N)

2. Suspend it  (Suspending a drop), and mark (M)  the voltage.  Write the voltage down as one of your voltages for that drop Getting and suspending a new drop

Determine its size (How to determine the size of a drop)

1. Bring it to the top of the screen, return to your marked voltage (R)   How to determine the size of a drop

2. Disconnect the voltage (D) start the timer on a new gridline (T) return to your marked voltage (R) when the timer runs out

3. Read the number of divisions to the nearest tenth of a division.   Write it down.  Check the micrometers per division.  (77.5 micrometers/division is best all around for this part.  You can Zoom out for Zap/Suspend)

4. Do this 3 times for a new drop

Zap/Suspend:  (It helps to zoom out at this point, but don't forget to zoom back in if you lose the drop)

1. Zap the drop. (Z)  (Zapping changes the charge, but not the size of the drop)   Zap Suspend Gathering data points 

2. Suspend the drop. (Suspending a drop) Write down the voltage if it is a unique voltage for that drop.  

Analysis and writeup:

Old Stuff for Excel

There is a glitch in MS Excel where the charge (maybe because it is so small) axis does not seem to be able to have gridlines.  You could use Excel anyway, and get along without horizontal gridlines - you can see what the numbers are in your data table anyway, or you can use Google Sheets which is free, and will do gridlines no problem.  The other approach would be to create another column which is the sorted charge x1019  (multiply it by this factor)  then Excel will remember how to do gridlines on the vertical axis.

Making the Spreadsheet (PC - MS Office 2010)