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 ...... $\text{T}$.

The Biot-Savart law for a moving point charge $q$ with velocity $\vec{v}$ is given by $\vec{B} = \frac{\mu_0}{4\pi} \frac{q(\vec{v} \times \vec{r})}{r^3}$. This indicates that the magnetic field $\vec{B}$ produced by an electron moving with velocity $\vec{v}$ is such that:

$A$ very long wire carrying a current $I = 4 \sqrt{2} \, A$ is bent at a right angle. The magnitude of the magnetic field $(|B|)$ at a point $P$ lying on a line perpendicular to the bent wire at a distance $d = 20 \, cm$ from the point of the bending will be (Let $\mu_0 = 4 \pi \times 10^{-7} \, H/m$): (in $\, \mu T$)

$A$ long straight wire of radius $a$ carries a steady current $I$. The current is uniformly distributed over its cross-section. The ratio of the magnetic fields $B$ and $B'$,at radial distances $\frac{a}{2}$ and $2a$ respectively,from the axis of the wire is

$A$ steady current flows in a long wire. It is bent into a circular loop of one turn and the magnetic field at the centre of the coil is $B$. If the same wire is bent into a circular loop of $n$ turns, the magnetic field at the centre of the coil is

Two similar coils, which are separated by $2 \ m$, have a radius of $1 \ m$ and $80$ turns, and share a common axis. Calculate the strength of the magnetic field in microtesla at a point midway between them on their common axis when the current is $0.2 \ A$.