A current .I. flows through a metallic wire of radius .r. and the free electrons in it drift with a velocity `v_(d)`. Calculate the drift velocity of the free electrons through the wire of the same material, having double the radius, when same current flows through it.

Options

A. `4v_(d)`
B. `v_(d)/4`
C. `16v_(d)`
D. `v_(d)/16`

Answer

C

Explanation

`therefore` Current, `I=nAev_(d)` or `V_(d) propto 1/A`
If diameter of wire is `d/4`, then area will be `A/16`, so new drift velocity = 16v_(d)`.