Flux (douglas) magnetization

[hd28cw]

Find the magnetic flux crossing the portion of the plane
theta = x/4 defined by 0.01 m < r <0.05 m and 0 m < z < 2 m. A current of 2.50 A is flowing along z-axis along a very long wire.

in drawing the picture i know that there is a long thin wire with a current of 2.5 amps flowing positively on the z-axis and the plane is lying rotated at an angle of pi/4 with the magnetic field flowing in a counter clockwise direction.

How do I go about finding the magnetic flux.
Please help.

[Astronuc]

Well first one has to find the magnetic field (B) at some distance r from the conductor.

This problem is a little complicated since one has a plane tilted at 45° from the plane passing through the conductor. If the plane was verticle, then the magnetic field would simply be a function of r.

But since the plane is tilted, as one ascends the plane, the distance from the conductor increases.

So can you write an equations for the distance of a point on the plane from the conductor.

Now since the plane is tilted pi/4 or 45°, a point on the tilted plane is a distance z from the vertical plane, so the distance (d) from the conductor is just d=sqrt(r^2+z^2).

See if can use that with the definition of magnetic flux.