In: Physics
An aluminum wire consists of the three segments shown in the following figure. The current in the top segment is 13A
Part B
For each of these three segments, find the current density J.
Part C
For each of these three segments, find the electric field E.
Part D
For each of these three segments, find the drift velocity vd.
Part E
For each of these three segments, find the electron current i.
a)
Current through each segment
Itop=Imid=Ibottom=13 A
b)
radius r=d/2
Current density
J=I/A =I/pir2
Jtop=13/(pi*(1*10-3)2=4.14*106 A/m2
Jmid=13/(pi*(0.5*10-3)2=1.66*107 A/m2
Jbottom=13/(pi*(1*10-3)2=4.14*106 A/m2
c)
E=J/sigma
Etop=(4.14*106)/(3.5*107)=0.1183 V/m
Emid=(1.66*107)/(3.5*107)=0.474 V/m
Ebottom=0.1183 V/m
d)
Drift velocity
Vd=J/ne
Vtop=(4.14*106)/(6*1028)(1.6*10-19) =4.31*10-4 m/s
Vmid=(1.66*107)/(1.6*10-19)(6*1028)=1.73*10-3 m/s
Vbottom=4.31*10-4 m/s
e)
electron current
Ie=I/e =13/(1.6*10-19) = 8.13*1019 electrons
Itop=8.13*1019 electrons
Imid=8.13*1019 electrons
Ibottom=8.13*1019 electrons