Two wires each of radius of cross section `r` but of different materials are connected together end to end (in series). If the densities of charge carries in the two wires are in the ratio `1:4`, the drift velocity of electrons in the two wires will be in the ratio:

Options

A. `1 : 2`
B. `2 : 1`
C. `4 : 1`
D. `1 : 4`

Answer

C

Explanation

Two wires carry same current
`I=n_(1)eA V_(d_(1)) =n_(2)eA Vd_(d_(2))`
so `n_(1)V_(d_(1))=n_(2)V_(d_(2))`
`(V_(d_(1)))/(V_(d_(2)))=(n_(2))/(n_(1))=4 rArr V_(d_(1)):V_(d_(2))=4:1`.