Two very long fixed wires cross each other at right angles. They do not touch but are
close to each other. Equal currents flow in each wire in the directions shown below.
Indicated the locus of points where the net magnetic field is zero.
B = m0I/2pir
The Attempt at a Solution
I know from the right hand rule that the magnetic field due to I1 will curl around towards me (out of the page) on top of the wire and point away from me (into the page) when directly below the wire.
The magnetic field due to I2 will point into the page when to the right of the wire and out of the page when to the left of the wire.
But it seems that the directions of the two fields will always be perpendicular to each other and thus never cancel out. How can there be a locus of points where the net magnetic field is 0?