\(\text { at } \mathrm{x}=0.04 \mathrm{~m}, \text { T.E. }=0.5+0.4=0.9 \mathrm{~J}\)
\(\text { T.E }=1 \mathrm{~m}^2 \mathrm{~A}^2=0.9\)
\(\quad=\frac{1}{2} \times 0.2\left(2 \pi \times \frac{25}{\pi}\right)^2 \times \mathrm{A}^2=0.9\)
\(\Rightarrow \mathrm{A}=0.06 \mathrm{~m}\)
\(\mathrm{~A}=6 \mathrm{~cm}\)