If A is the area of cross section of conductor, `v_(d)` is the drift velocity of electrons and n is the number of electrons per unit volume, then current density through conductor is

Options

A. ne `v_(d)`
B. `(n e A)/(v_(d))`
C. `(n e v_(d))/(A)`
D. `(n/a)A v_(d)`

Answer

A

Explanation

`J=(I)/(A)=(q)/(tA)=(nA l e )/(tA)= (n l e )/(t)=n e v_(d)`