Question
The current density in a cylindrical wire of radius 4 mm is 4 $\times$ 106 Am$-$2. The current through the outer portion of the wire between radial distances ${R \over 2}$ and R is ____________ $\pi$ A.
Correct Answer
48
The current density in a cylindrical wire of radius 4 mm is 4 $\times$ 106 Am$-$2. The current through the outer portion of the wire between radial distances ${R \over 2}$ and R is ____________ $\pi$ A.