A fluxgate magnetometer consists of a small, magnetically susceptible core wrapped by two coils of wire.
Case knew the thing for what it was as it broke the surface: a core of high explosive wrapped with ten meters of fine, brittle steel wire.
Fly lines consist of a tough braided or monofilament core, wrapped in a thick waterproof plastic sheath, often of polyvinyl chloride (PVC).
Instrument analysis disclosed it to consist of a dense lithic core wrapped in a mantle of frozen ammonia, methane, and other gaseous compounds.
Today, in most fabrics, zari is not made of real gold and silver, but has cotton or polyester yarn at its core, wrapped by golden/silver metallic yarn.
Current transformers are often constructed by passing a single primary turn (either an insulated cable or an uninsulated bus bar) through a well-insulated toroidal core wrapped with many turns of wire.
It is generally a loose or untwisted core wrapped by at least one other strand.
Igniter cord in construction is again similar to safety fuse, consisting of a pyrotechnic composition at the core, wrapped with a nylon sheath to provide shape and finally wrapped again in an outer plastic shell to provide water resistance.
