A circular conductor with the current

and the radius

lies in the

plane at

. The vector potential

in the

direction as a function of

and

has the same symmetry as the current density in cylindrical coordinates

,

,

. According to the cylindrical symmetry the observation points in the

plane can be taken at

. The source is described by the angle

, running from

to

. The following computations are made:

• the magnetic field

in the

direction

• the magnetic field

in the

direction

• the magnetic energy density

• the integrated magnetic field

in the

direction

• the integrated magnetic field

in the

direction

• the integrated magnetic energy density

• the integrated vector potential

in the

direction

The fields at

can be regarded as a good approximation of the integrated fields. The four field

,

,

,

are displayed for the four independent variables

,

,

,

. The observation points are described by

,

and the source by

,

.