Question

which of the following is an example of a ground in a building?
a pipe to the ground
a metal rod in the air
a plastic rod
an extra electrical cord.

Explanation:

A building ground provides a safe path for electrical current to dissipate into the earth. A pipe connected directly to the earth fulfills this purpose. A metal rod in air doesn't connect to the ground, plastic is an insulator that can't conduct current to the ground, and an extra electrical cord doesn't serve as a grounding path to the earth.

Answer:

A. A pipe to the ground