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

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

The magnetic field intensity $(H)$ at the centre of a long solenoid carrying a current of $2 \ A$ is found to be $1000 \ A/m$. The number of turns per centimeter of the solenoid is: (Use $\mu_0 = 4 \pi \times 10^{-7} \ T \ m \ A^{-1}$)

$A$ long cylindrical wire of radius $R$ carries a uniform current $I$ flowing through it. The variation of magnetic field $B$ with distance $r$ from the axis of the wire is shown by:

$A$ solenoid of length $2 \ m$ carries a current of $20 \ A$. The diameter of the solenoid is $3 \ cm$. If the magnetic field inside the solenoid is $20 \ mT$, then the length of wire forming the solenoid is (assume $\mu_0 = 4 \pi \times 10^{-7} \ H/m$) (in $m$)

$A$ long solenoid carrying a current produces a magnetic field $B$ along its axis. If the current is tripled and the number of turns per cm is halved, then the new value of the magnetic field will be: