A regular polygon of $6$ sides is formed by bending

a wire of length $4 \pi$ meter. If an electric current of $4 \pi \sqrt{3} \mathrm{~A}$ is flowing through the sides of the polygon, the magnetic field at the centre of the polygon would be $x \times 10^{7} \mathrm{~T}$. The value of $\mathrm{x}$ is______.

Give Oersted’s observation.

Given below are two statements$:$

Statement $I:$ Biot-Savart's law gives us the expression for the magnetic field strength of an infinitesimal current element (IdI) of a current carrying conductor only.

Statement $II :$ Biot-Savart's law is analogous to Coulomb's inverse square law of charge $q$, with the former being related to the field produced by a scalar source, Idl while the latter being produced by a vector source, $q$. In light of above statements choose the most appropriate answer from the options given below:

An electron moving in a circular orbit of radius $r$ makes $n$ rotation per second. The magnetic field produced at the centre has a magnitude of

Three infinite wires are arranged in space in three dimensions.(along $x, y$ and $z$ axis) as shown. Each wire carries current $i$ . Find magnetic field at $A$ 

Find out magnetic field at point $O$ ?