![\"\"](\"http:\/\/commons.princeton.edu\/josephhenry\/wp-content\/uploads\/sites\/71\/2018\/07\/Saturation.png\")
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![\"\"](\"http:\/\/commons.princeton.edu\/josephhenry\/wp-content\/uploads\/sites\/71\/2018\/07\/ElectromagnetGraph.tif_.jpeg\")
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The experimental data (exp 8 – 14) shows an exponential shape before saturating and leveling off. This can be compared to the a theoretical saturation of both wrought and cast iron in the figure above. As shown, the material Henry used was somewhere between The value of H for Henry’s data depends on the amount of current drawn from the galvanic cell, which depends on a currently unknown value of internal resistance. However, we estimate the resistance of his single galvanic cell to be fairly high, somewhere around 5 ohms. The first 4 points on the graph are offset from the fit line, showing the diminishing loss of magnetic flux density due to the leakage of magnetic force lines.<\/p>\n
(The Electrical Engineer, Vol.11 (July 1893): pp.95,173)<\/p>\n
The following MATLAB syntax was used to construct this comparison.<\/p>\n
hold on<\/p>\n
H1=[0,1.66,4,5,6.5,8.5,12,17,28.5,50,105,200,350,660].\/(4.*pi.\/10);%Magnetomotive force in ampere-turns
\nB1=[0,5000,9000,10000,11000,12000,13000,14000,15000,16000,17000,18000,19000,20000].*(.0001); %Flux Density is Tesla
\nF1=(((2.*(B1.^2).*(4.*(.0254.^2))).\/(2.*u0))).*0.224808943; %Force in Pounds
\np1=plot(H1,F1,’-‘);<\/p>\n
H2=[0,5,10,21.5,42,80,127,188,292].\/(4.*pi.\/10);
\nB2=[0,4000,5000,6000,7000,8000,9000,10000,11000].*(.0001);
\nF2=(((2.*(B2.^2).*(4.*(.0254.^2))).\/(2.*u0))).*0.224808943;
\np2=plot(H2,F2,’–‘);<\/p>\n
coils=[0,1,2,2,3,4,6,9]; %Data from Joseph Henry’s Paper
\nweight=[0,7,145,200,300,500,570,650];<\/p>\n
d=.045*(.0254); %Diameter of the wire used in meters
\nA=pi*(d\/2)^2; %Cross sectional area of the wire used
\nL_c=60*12*(.0254); %Length of wire used in each coil in meters
\nro=1.68*10^-8; %Resistivity in ohm-m
\nR_L=ro*L_c\/A; %Resistance of each coil
\nR_S=5; %Resistance of the galvanic cell, assuming the batteries
\n%he used had fairly high resistance compared to modern batteries.
\nR=R_L+R_S; %Total Resistance of Circuit
\nI=(1\/(R)); %Current in each coil
\nN=coils.*80; %Number of turns
\nH=((I.*N)); %Magnetomotive force in ampere-turns<\/p>\n
p3=plot(H,weight,’o’)
\nxlabel(‘H (Ampere-Turns)’)
\nylabel(‘Weight (lb)’)<\/p>\n
legend([p1,p2,p3],’Wrought Iron’,’Cast Iron’,’Henrys Experiment’,1)<\/p>\n","protected":false},"excerpt":{"rendered":"
Data Analysis – Theoretical Comparison The experimental data (exp 8 – 14) shows an exponential shape before saturating and leveling off. This can be compared to the a theoretical saturation of both wrought and cast iron in the figure above. As shown, the material Henry used was somewhere between The value of H for Henry’s … Continue reading “Analysis”<\/span><\/a><\/p>\n","protected":false},"author":5,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-3315","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/pages\/3315","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/comments?post=3315"}],"version-history":[{"count":3,"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/pages\/3315\/revisions"}],"predecessor-version":[{"id":3797,"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/pages\/3315\/revisions\/3797"}],"wp:attachment":[{"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/media?parent=3315"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/categories?post=3315"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/commons.princeton.edu\/josephhenry\/wp-json\/wp\/v2\/tags?post=3315"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}