Which of the following materials is the best conductor of electricity?

COPPER is an excellent CONDUCTOR of electricity (which is why it's widely used in wiring). ASVAB Electronics Information tests conductors vs insulators. CONDUCTORS (allow current to flow easily): metals like copper, silver (best), gold, aluminum. INSULATORS (resist current flow): rubber, glass, plastic, wood, ceramic — used to insulate and protect. Silver is the best conductor, but copper is most common (cheaper, still excellent). Wires are copper conductors covered in rubber/plastic insulation. Knowing copper is a good conductor and rubber/glass/wood are insulators is commonly tested.