Answer:
The principal hair fiber used to produce textile fabrics is sheep's wool. In wild sheep, the wool is a short, soft underlayer protected by longer, coarser hair. ... Fur fibers from animals such as mink and beavers are sometimes blended with other hairs to spin luxury yarns but are most often found as fur pelts.
when we need to represent the magnetic field in a specific region where it is given that magnetic field lines are perpendicular to the plane and going inside the plane then we always use the concept of representation by "X"
here this symbol represents that field lines are going into the plane
it is also the uniform magnetic field always
so the correct answer would be
<u>Magnetic Field</u>
