If $B$ is the magnetic field and $\mu_0$ is the permeability of free space,then the dimensions of $(B / \mu_0)$ are:

Rank the value of $\oint \vec{B} \cdot d\vec{l}$ for the closed paths shown in the figure from the smallest to largest.

$A$ long solenoid produces a magnetic field $B$ on its axis. If it is cut into four equal parts and,for the same current,half the number of turns are wound on any one piece,the value of the magnetic field on its axis becomes:

$A$ solenoid has a length of $0.4 \,m$, a radius of $1 \,cm$, and $400$ turns of wire. If a current of $5 \,A$ is passed through this solenoid, what is the magnetic field inside the solenoid?

The magnetic induction produced inside an ideal solenoid depends on which of the following quantities?
$(a)$ Number of turns per unit length $(n)$.
$(b)$ Radius of the wire.
$(c)$ Current flowing through it $(I)$.
$(d)$ Permeability of the medium $(\mu)$.

$A$ toroid is: