Physics307L:People/Mondragon/Notebook/070919

Excel File
Here is the [[Media:Lab_2_e_m_calculation.xls|Excel File]] that Lorenzo uploaded.

Mass of the Electron(second week)
##this script is here to document the steps I took in processing data from the e/m ratio experiment. Hoorah.


 * 1) octave
 * 2) runs best in octave, then matlab

varyAleft=[200,200,200,200   #ring radius on the left, varying current 1,1.2,1.4,1.6                #first row is voltage, second is current 4.9,4.8,4.6,4.5              #third is radius, and fourt is error on radius 0.2,0.2,0.3,0.3]             #units are volts, amperes, centimeters, cm

varyAright=[200,200,200,200   #ring radius on the right, varying current 1,1.2,1.4,1.6 4.3,3.7,3.2,3.1 0.1,0.2,0.1,0.2]

varyVright=[200,220,240,260   #ring radius on the right, varying voltage 1,1,1,1 4.3,4.5,4.7,4.8 0.2,0.1,0.2,0.1]

varyVleft=[200,220,240,260   #ring radius on the left, varying voltage 1,1,1,1 4.8,4.9,5.1,5.2 0.2,0.1,0.2,0.3]

Verror=1 Aerror=0.01
 * 1) the voltage and current uncertainties were constant, so, just assign constants for their error

rawData=[varyAleft varyAright varyVleft varyVright]
 * 1) Clump all the data in one variable for convienence purposes

Bmagnitude=7.8e-4*rawData(2,:) BmagnitudeError=Aerror*7.8e-4     #propagate error via chain rule
 * 1) compute the bfield strength according to the current

e_mRatio=2*rawData(1,:)./(Bmagnitude.^2.*(rawData(3,:)*10^(-2)).^2)
 * 1) e/m ratio computation. e/m= 2*voltage/(Bfield^2*radius(in meters)^2)

e_mError=2*Verror./(Bmagnitude.^2.*(rawData(3,:)*10^(-2)).^2+4*BmagnitudeError*rawData(1,:)./(Bmagnitude.^3.*(rawData(3,:)*10^(-2)).^2)+4*rawData(1,:).*rawData(4,:)*10^(-2)./(Bmagnitude.^2.*(rawData(3,:)*10^(-2)).^3) --Tomas A. Mondragon 14:45, 10 October 2007 (CDT)