Question

Two different wires X and Y of same diameter but different materials are joined in series across a battery. If the number density of electrons in X is twice that in Y, find the ratio of drift velocity of electrons in the two wires .

Answer 1

Drift velocity,
`v_(d) = (I)/(n A e) = I/(n(pi D^(2)//4)e),` i.e., `v_(d) prop1/n`
Since the wires are connected in series, current `I` through both is same. Therefore,
`((v_(d))_(x))/((v_(d))_(y)) = n_(y)/n_(x) = 1/2`