User:Richard T. Meyers/Notebook/Phys307l/E/m Lab
ProcedureSJK 22:22, 13 October 2010 (EDT)
The Procedure that we followed can be found here
EquipmentSJK 22:17, 13 October 2010 (EDT)
6-9V Power supply rated at 2A (Gelman Deluxe Regulated Power Supply)
Power supply of 6.0V max rated at 1.5A (Soar DC Power Supply model PS 3630)
150-300V power supply rated at 40mA (Hewlett Packard 6236B)
e/m Experimental Apparatus
At first we use the equation for the magnetic field
So from this we know that:
Then we can say that since
so we get
Also from the data of the plot of
this is just the inverse of the slope of second chart converted from cm to m, and the average current is
The second approximation of e/m is as follows:
from the plot of radius versus inverse current we get:
So we can use the slope of the first graph to say
The accepted value of e/m is
ErrorSJK 22:20, 13 October 2010 (EDT)
With our accepted value at:
and the two calculated values at:
we can obviously see that there is a large discrepancy with the data.
One set is large and the other is small so we assume that the correct number is somewhere between the two.
So the average of the two gets:
Compare this with the actual number and we get and error of:
This error for the amount of data points taken is not unreasonable.SJK 22:19, 13 October 2010 (EDT)
1) I found the accepted value of e/m here
1)Nathan for being my excellent lab partner and for taking down the equipment list when I had failed to.
2)Emran for setting up the lab previously and for a general outline of my report.
3)Randy also for setting up the lab previously.