Two long wires with no contact are placed perpendicular to each other. $i,$ and $i_2,$ are currents flowing through these wires respectively. The magnetic force on a small length $\text{'}d\text{'}$ of the second wire situated at a distance $\text{'}l\text{'}$ from, the first wire is proportional to, 

In the diagram shown, I₁, I₂ are the magnitude of current in the square loop and infinite long straight conductor respectively. The net magnetic field at the centre of loop is zero, then

In the figure shown, there are two semicircles of radii $r_1$ and $r_2$ in which a current $i$ is flowing. The magnetic induction at the Centre $O$ will be

Find the magnetic field at point $\mathrm{P}$ due to a straight line segment $\mathrm{A}\mathrm{B}$ of length $6 \mathrm{c}\mathrm{m}$ carrying a current of $5 \mathrm{A}.$ (See figure) $\left({\mu }_0=4\pi \times {10}^{-7} {\mathrm{NA}}^{-2}\right)$

Two very long, straight, and insulated wires are kept at $90°$ angle from each other in $\mathrm{x}\mathrm{y}$ plane as shown in the figure.

These wires carry currents of equal magnitude $I$ , whose direction are shown in the figure. The net magnetic field at point $P$ will be:

As shown in the figure, two infinitely long, identical wires are bent by ${90}^o$ and placed in such a way that the segments $LP$ and $QM$ are along the $x$ - axis, while segments $PS$ and $QN$ are parallel to the $y$ - axis. If $OP=OQ=4cm,$ and the magnitude of the magnetic field at $O$ is ${10}^{-4} T,$ and the two wires carry equal currents (see figure), the magnitude of the current in each wire and the direction of the magnetic field at $O$ will be $\left({\mu }_0=4\pi \times {10}^{-7}N{A}^{-2}\right):$