The drift velocity of the electrons in a copper wire of length 2 m under the application of a potential difference of 220V is `0.5ms^-1` . Their mobility ( in `m^2v^-1s^-1`)

Options

A. `2.5 xx 10^(-3)`
B. `2.5 xx 10^(-2)`
C. `5 xx 10^(2)`
D. `5 xx 10^(-3)`

Answer

D

Explanation

`v_(d) = 0.5 m//s, E = V/l = 200/2 = 100 V//m`
Mobility `= mu = v_(d)/E = 0.5/100 = 5 xx 10^(-3) m^(2)//Vs`