Question

0 meaning of a soft iron core in which the coil is wound

Answer 1

The iron core and coil are the basic elements of an electromagnet. The material used in the core is chosen because it does not become magnetized permanently as this would produce errors in the operation of the meter.

If a material was chosen that retained a permanent magnetic field, then the meter would indicate current flow when none was actually there as the residual magnetism would produce a force that deflected the pointer away from zero indication.