The unloading system on an air compressor will __________.

Correct Answer: Option D — allow the motor to turn the compressor opposed only by friction

An unloading system prevents the compressor motor from starting under full load. By bypassing the compression process, the motor only encounters the frictional resistance of the moving parts. This reduces the starting torque requirements, prevents motor burnout, and allows the compressor to reach operating speed before engaging the load.