To have a uniform field. The field is the voltage between the plates divided by the distance between the plates. If the distance varies so would the field between them.
<h2>Answer:</h2>
0
<h2>Explanation:</h2>
Since the current carrying wire is placed along the axis of the cylinder, according to the right hand rule, the magnetic field will be tangent to the surface of the cylinder. Therefore, there is no magnetic field through the cylinder.
Remember that the magnetic flux through a given area is the total magnetic field passing through that area. Since there is not magnetic field through the cylinder, the total magnetic flux is therefore zero (0).
