
$\Rightarrow \frac{\mu_{0} i R^{2}}{2\left(x^{2}+R^{2}\right)^{3 / 2}}$
And hence for $N$ turns is,
$\Rightarrow \frac{\mu_{0} \mathrm{NiR}^{2}}{2\left(\mathrm{R}^{2}+\mathrm{x}^{2}\right)^{3 / 2}}$

The ratio of the radii of trajectory of proton to that of $\alpha$ -particle is $2: 1 .$ The ratio of $K _{ p }: K _{\alpha}$ is :

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: