Current Flow and Mobility Find the current flow through a copper wire of length 0.2 m, area of cross-section 1 `mm^(2)` , when connected to a battery of 4 V. Given that electron mobility is `4.5 xx 10^(-6) m^(2) s^(-1) V^(-1)` and charge on an electron is `1.6xx10^(-19)` C. The number density of electron in copper wire is `8.5 xx 10^(28) m^(3)` .

Explanation

Given length of copper wire l=0.2 m cross sectional area `A=1 mm^(2) =10^(-6) m^(2)`
charge of an electron `e=1.6 xx10^(-19) C`
we known that electric field set up across the conductor `=8.5 xx10^(28) xx10^(6)xx1.6 xx10^(-19) xx4.5 xx10^(-6) xx20`
=1.22 A