A long straight metal rod has a very long hole of radius $$a$$ drilled parallel to the rod axis as shown in the figure. If the rod carries a current $$i$$ find the value of magnetic induction on the axis of the hole, where OC = c

A

$$\frac{\mu_0ic}{\pi\left(b^2-a^2\right)}$$

B

$$\frac{\mu_0ic}{2\pi\left(b^2-a^2\right)}$$

C

$$\frac{\mu_0i\left(b^2-a^2\right)}{2\pi c}$$

D

$$\frac{\mu_0ic}{2\pi ab}$$