Two coaxial loops of different radii such as
and
are placed as shown in the figure. What should be the magnitude and direction of the current in the loop
so that the net magnetic field at the point
be zeno

The resultant magnetic field at the point will be zeno only if the direction of current in loop
is opposite to that on loop
Then magnetic field at
due to current
in loop
magnetic field at
dur to current
in loop