The mean free path of conduction electorns in copper is about `4xx10^(-8)`m. for a copper block, find the electric field which can give, on an average, 1eV energy to a conduction electron.

Explanation

Lets the electric field be E, The force on an electorn is eE. As the electron moves through a distance d, the work done on it is eEd. This is equal to the energy transferred to the electron. As the electron travels an average distance of `4xx10^(-8)`m before a collision ,the energy transferred is `eE(4xx10^(-8)m).to get 1eV energy form the electric field,
`eE(4xx10^(-8)m)=1eV`
or,E=2.5xx10(7)Vm^(-1).`