  Magnetic fields are the primary driver of the plasma thermodynamics in the
upper solar atmosphere, especially in the corona. However, magnetic field
measurements in the solar corona are sporadic, thereby limiting us from the
complete understanding of physical processes occurring in the coronal plasma.
In this paper, we explore the diagnostic potential of a coronal emission line
in the extreme-ultraviolet (EUV), i.e., Ne VIII 770 \AA to probe the coronal
magnetic fields. We utilize 3D 'Magneto-hydrodynamic Algorithm outside a
Sphere' (MAS) models as input to the FORWARD code to model polarization in Ne
VIII line produced due to resonance scattering, and interpret its modification
due to collisions and the magnetic fields through the Hanle effect. The
polarization maps are synthesized both on the disk as well as off-the-limb. The
variation of this polarization signal through the different phases of solar
cycle 24 and the beginning phase of solar cycle 25 is studied in order to
understand the magnetic diagnostic properties of this line owing to different
physical conditions in the solar atmosphere. The detectability of the linear
polarization signatures of the Hanle effect significantly improves with
increasing solar activity, consistently with the increase in the magnetic field
strength and the intensity of the mean solar brightness at these wavelengths.
We finally discuss the signal-to-noise ratio (SNR) requirements by considering
realistic instrument designs.
