\(\mathrm{C} \theta=\mathrm{BINA} \sin 90^{\circ}\)
\(\mathrm{C}=\frac{\mathrm{BINA}}{\theta}=\frac{0.01 \times 10 \times 10^{-3} \times 100 \times 2 \times 10^{-4}}{0.05}\)
\(=4 \times 10^{-5} \mathrm{~N}-\mathrm{m} / \mathrm{rad} .\)
\(\mathrm{x}=4\)