Question

in a motor, the commutator: a) sets up the magnetic field b) transfers current c) is an electromagnet d) uses segments to reverse current

Explanation:

A commutator in a motor has segments that reverse the current direction in the armature coil as it rotates. This helps in continuous rotation of the motor. It is not responsible for setting up the magnetic field (usually done by permanent - magnets or field - coils), not just for transferring current, and is not an electromagnet itself.

Answer:

D. Uses segments to reverse current