\(\Rightarrow  \frac{B}{\mu_{0}}=n i\)

(Where \(n=\) number of turns per unit length)

\(\Rightarrow  \frac{B}{\mu_{\theta}}=\frac{N i}{L}\)

\(\Rightarrow  3 \times 10^{3}=\frac{100 i}{10 \times 10^{-2}}\)

\(\Rightarrow i=3\, \mathrm{A}\)