The $SI$ unit of magnetic permeability is

Given below are two statements:
Statement $(I)$: When currents vary with time,Newton's third law is valid only if momentum carried by the electromagnetic field is taken into account.
Statement $(II)$: Ampere's circuital law does not depend on Biot-Savart's law.
In the light of the above statements,choose the correct answer from the options given below:

Calculate the magnetic field at point $M$ for the given current distribution.

The magnetic field at the centre of a circular coil of radius $r$ carrying current $I$ is $B_1$. The field at the centre of another coil of radius $2r$ carrying the same current $I$ is $B_2$. The ratio $\frac{B_1}{B_2}$ is

$A$ steady electric current is flowing through a cylindrical wire. Which of the following statements is/are correct?
$(a)$ The electric field at the axis of the wire is zero.
$(b)$ The magnetic field at the axis of the wire is zero.
$(c)$ The electric field in the vicinity of the wire is zero.
$(d)$ The magnetic field in the vicinity of the wire is zero.

The magnitude of the magnetic field at $O$ due to a current-carrying loop as shown in the figure is, where $O$ is the center of two circular portions with radii $1 \, cm$ and $2 \, cm$ respectively. (Take the value of current $I = \frac{1.2}{\pi} \, A$)