\(=\frac{10}{100} \times 110\,W\)

\(=11\,W\)

\(I _{1}- I _{2}=\frac{ P ^{\prime}}{4 \pi r _{1}^{2}}-\frac{ P ^{\prime}}{4 \pi r _{2}^{2}}\)

\(=\frac{11}{4 \pi}\left[\frac{1}{1}-\frac{1}{25}\right]\)

\(=\frac{11}{4 \pi} \times \frac{24}{25}\)

\(=\frac{264}{\pi} \times 10^{-2}=84 \times 10^{-2}\,W / m ^{2}\)