The current density in a medium is given by $${\overrightarrow J= \frac{400 \sin\theta}{2\pi(r^2+4)} \hat {a}_r \: Am^{-2}}$$
The total current and the average current density flowing through the portion of a spherical surface $r = 0.8 \: m$, $\frac{\pi}{12} \leq \theta \leq \frac{\pi}{4}$, $0 \leq \phi \leq 2\pi$ are given, respectively, by
- $15.09 A, \: 12.86 Am^{-2}$
- $18.73 A, \: 13.65 Am^{-2}$
- $12.86 A, \: 9.23 Am^{-2}$
- $10.28 A, \: 7.56 Am^{-2}$