A uniform copper wire of length `1m` and cross section area `5 xx 10^(-7)m^(2)` carries a current of `1A`. Assuming that are `8 xx 10^(28)` free electron per `m^(3)` in copper, how long will an electron take to drift from one end of the wire an electron the other. Charge on an electron `= 1.6 xx 10^(-19)C`

Answer

`6.4 xx 10^(3) s`

Explanation

`t = (l)/(upsilon_(d)) = (l)/(I//nAe) = (l n A e)/(I)`
`= (1 xx (8 xx 10^(28)) xx (5 xx 10^(-7)) xx (1.6 xx 10^(-19)))/(1)`
`= 6.4 xx 10^(3) s`