Question

Magnetic lines of force around any current carrying conductor are circular in nature.

Answer 1

Magnetic lines around the current carrying conductor is referred to as flux,just as in natural magnet,the field is strongest near the wire and diminishes as the distance from wire increases radially as following formula

$\overrightarrow{B}=\frac{{\mu }_{0}I}{2\pi r}$ and

$\overrightarrow{B}\propto \frac{1}{r}$