\(\text { Also, } \mathrm{F}=\mathrm{i} \ell \mathrm{B}\)
\(\Rightarrow \mathrm{F}_1=\mathrm{i} \ell \mathrm{B}_0 \& \mathrm{~F}_2=9 \mathrm{i} \ell \mathrm{B}_0\)
\(\mathrm{~F}=\mathrm{F}_2-\mathrm{F}_1=8 \mathrm{i} \ell \mathrm{B}_0=8 \times 2 \times 2 \times 5\)
\(\mathrm{~F}=160 \mathrm{~N}\)