A cylindrical wire if radius R = 2 mm is of uniform area of cross-section. The current density
Channel: Doubtnut
Date: 2020-08-23

A cylindrical wire if radius R = 2 mm is of uniform area of cross-section. The current density through a cross-section varies with radial distance r as `J = ar^(2)`, where `a =3.2 xx 10^(11)A//m^(2)` and r is in metres. What is the current through the outer portion of the wire between radial distances `R//2` and R?