Two long straight parallel wires carry currents of $8 \ A$ and $10 \ A$ in opposite directions. If the distance of separation between the wires is $9 \ cm$, then the net magnetic field at a point between the two wires, which is at a perpendicular distance of $4 \ cm$ from the wire carrying $8 \ A$ current is:

The magnetic field due to a straight conductor of uniform cross-section of radius $a$ and carrying a steady current is represented by

Magnetic field induction at the centre of a circular coil of radius $5 \,cm$ and carrying a current $0.9 \,A$ is (in $SI$ units) (where $\varepsilon_0$ is the absolute permittivity of air in $SI$ units,and the velocity of light $c = 3 \times 10^8 \,ms^{-1}$)

$A$ current of $I$ $A$ is passed through a straight wire of length $2.0$ $m$. The magnetic field at a point in air at a distance of $3$ $m$ from either end of the wire and lying on the axis of the wire will be:

$A$ long curved conductor carries a current $I$. $A$ small current element of length $dl$ on the wire induces a magnetic field at a point away from the current element. If the position vector between the current element and the point is $\vec{r}$,making an angle $\theta$ with the current element,then the induced magnetic field density $d\vec{B}$ at the point is $(\mu_0 = \text{permeability of free space})$:

Two infinitely long wires carry currents $4 \text{ A}$ and $3 \text{ A}$ placed along the $X$-axis and $Y$-axis respectively. The magnetic field at a point $P(0, 0, d) \text{ m}$ will be ...... $\text{T}$.