There will always be some amount of current flow in the primary of any voltage transformer even if there is no load connected to the secondary. This is called the relaxation current of the transformer.

Question

Quizplus · Accepted Answer

The current that flows in the primary of a transformer with no load on the secondary is called the magnetizing current, not the relaxation current. This current is necessary to establish the magnetic field in the transformer's core.

There Will Always Be Some Amount of Current Flow in the Primary