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 .

Explanation

The current I through the wire is related with drift velocity vd is given by I = n A `e v_(d)`.
Since two wires X and Y of same diameter but different materials are joined in series .
`therefore " " I_(x) = I_(y)`
`therefore " " n_(x) A ev_(dx) = n_y Ae v_(dy)`
`2 n_(y) A e v_(dx) = n_(y) Ae v_(dy) implies (v_(dx))/(v_(dy)) = (1)/(2) v_(dx) : v_(dy) = 1 : 2`