Two straight long conductors $AOB$ and $COD$ are perpendicular to each other and carry currents $I_1$ and $I_2$ respectively. Find the magnitude of the magnetic field at point $P$ at a distance a from the point $O$ in a direction perpendicular to the plane $ABCD$ABCD.

Two insulating infinitely long conductors carrying currents $I_1$ and $I_2$ lie mutually perpendicular to each other in the same plane as shown in figure. Find the magnetic field at point $P(a,b)$.

Two identical circular wires $P$ and $Q$ each of radius $R$ and carrying current $‘I’$ are kept in perpendicular planes such that they have a common centre as shown in figure. Find the magnitude and direction of the net magnetic field at the common centre of the two coils.

Two identical loops $P$ and $Q$ each of radius $5 \mathrm{cm}$ are lying in perpendicular planes such that they have a common centre as shown in the figure. Find the magnitude and direction of the net magnetic field at the common centre of the two coils, if the carry currents equal to $3 A$ and $4 A$ respectively.