20-33 First, find the magnetic field magnitude for each wire at a distance of 10 cm away. Since the currents are perpendicular to one another, their magnetic fields will be perpendicular as well. Each magnetic field line would represent one vector. Since these vectors are at right angles to one another, the resultant vector would the hypotenuse. There are a number of equations for magnetic fields.
L is the length of the coil.
In this case, the magnetic field is not perpendicular. However, you can find the component which is perpendicular. It is that component which you should use in the equation. Use the sine function. 20-61 Find the density of copper.