Every atom makes one free electron in copper. If 1.1 A current is flowing in the wire of copper having 1 mm diameter, then the drift velocity (approx.) will be (density of copper `=9xx10^(3)" kg m"^(-3) and " atomic weight of copper "=63)`

Options

A. `0.01 mm s^(-1)`
B. `0.02mm s^(-1)`
C. `0.2 mm s^(-1)`
D. `0.1 mm s^(-1)`

Answer

4

Explanation

No. of atom in 1 gm `Cu=(N_(A))/(63)`
No. of atom/`cm^(3)=(N_(A))/( 63)xx9`
`because` each atom contributes one electron
So no. of electron `(n)//m^(3)=(N_(A))/(63)xx9xx10^(6)`
Now I=`"ne"Av_(d)`
Put values I,n,e,A and calculate for `v_(d)`