To properly use a clamp-on-type ammeter to check current flow, what must be done FIRST?

Correct Answer: Option D — hook the jaws of the instrument around the insulated single conductor

Safe operation of a clamp-on ammeter requires encircling only a single insulated conductor first. Enclosing a multi-conductor cable cancels opposing magnetic fields, rendering a zero reading, while improper handling near uninsulated busbars violates IEEE 45 and marine electrical safety standards.