A circular coil of 100 turns and radius 10 cm carries a current of 5 A. The magnetic field at its centre is (\(\mu_0=4\pi\times10^{-7}\) T m/A)
A. \(2\pi\times10^{-3}\) T
B. \(\frac{\pi}{2}\times10^{-3}\) T
C. \(\pi\times10^{-4}\) T
D. \(\pi\times10^{-3}\) T