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A copper wire of 10^(-6)m^(2) are of cross section, carries a current of 2A. If the number of electrons per cubic meter is 8xx10^(28), calculate the current density and average drift velocity. |
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Answer» Solution : Cross-sections area of copper wire, A -=`10^(-6)m^(2)` 1 = 2A Number of electron, n = `8xx10^(28)` Current density, J= `(1)/(A)=(2)/(10^(-6))` J=`2xx10^(6)Àm^(-2)` AVERAGE drift velocity, `V_(d)=(1)/(n EA)` e is the charge of electron = `1.6xx10^(-9)C` `V_(d)=(2)/(8xx10^(28)xx1.6xx10^(-19)xx10^(-6))=(1)/(64xx10^(3))` `V_(d)=0.15625xx10^(-3)`,`V_(d)=15.6xx10^(-5)MS^(-1)` |
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