$1 \ T = \dots \text{Gauss}$.

Write the formula for the force per unit length between two parallel,current-carrying conducting wires.

$A$ small cube of side $1 \ mm$ is placed at the center of a circular loop of radius $20 \ cm$. If the current in the loop is $2 \ A$,then the magnetic energy stored inside the cube is (Assume $\mu_0 = 4 \pi \times 10^{-7} \ SI$ units).

The $SI$ unit of magnetic permeability is

Write the formula for the magnetic field at a point on the axis of a circular current-carrying loop of radius $R$ at a distance $x$ from its center,where $x >> R$.

The magnetic field at a perpendicular distance of $1 \,m$ from a long straight wire carrying a current of $1 \,A$ is: