A potential difference V is applied to copper wire fo diameter d and lengt L, what will be the effect on, the electron drift speed by doubling (a) voltage V, (b) length L, and (c ) diameter d?

Explanation

According to elerctron theory of metals, the dirft speed of an
electron inside a metal in the presence of an electric field E is
given by `v_d = ((etau)/(m)) E = ((etau)/(m))((V)/(L)) [ as E= (V)/(L)]`
a. As `vd propV,` on doubing V, drift velcoity will be doubled.
b.As `v_d prop(1//L),` on doubling L, drift velcoity will be halved.
c. As dirft veocity is independent of diameter d, it will not
charge on doubling the diameter.