magnetism Questions

A long solenoid of radius $1\text{mm}$ has $100\text{turns per mm}$. If $1\text{A}$ current flows in the solenoid, the magnetic field strength at the centre of the solenoid is:

The dimensions $[ML{T}^{-2}{A}^{-2}]$ belong to the:

Given below are two statements:Statement I: Biot-Savart's law gives the expression for the magnetic field strength of an infinitesimal current element ($Idl$) 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 Ampere’s circuital law for a long straight wire of circular cross-section carrying a steady current, the variation of magnetic field in the inside and outside region of the wire is: