
At equilibrium
$\mathrm{T} \cos \theta=\lambda \mathrm{g} \ell$
and $T \sin \theta=\frac{\mu_{0}}{2 \pi} \frac{I \times I l}{2 L \sin \theta}\left[\because \frac{F_{B}}{\ell}=\frac{\mu_{0}}{4 \pi} \frac{2 I \times I}{2 \ell \sin \theta}\right]$
Therefore, $I=2 \sin \theta \sqrt{\frac{\pi \lambda g L}{u_{0} \cos \theta}}$

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:

