Question

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

Answer 1

Correct Answer - C
`I=n_(1) eAv_(d_(1))=n_(2)eAv_(d_(2))`
`implies (v_(d_(1)))/(v_(d_(2)))=(n_(2))/(n_(1))=4/1`