Question

a device that increases or decreases voltage in a power line is a ____. transformer motor. commutator. generator

Explanation:

A transformer is an electrical device that uses electromagnetic induction to change the voltage level in a power - line. A motor converts electrical energy into mechanical energy, a commutator is part of a DC motor or generator to reverse the direction of current, and a generator converts mechanical energy into electrical energy.

Answer:

A. transformer