The path of the magnetic flux in transformer should have

The correct answer is: low reluctance.

Reluctance is the opposition to the flow of magnetic flux in a magnetic circuit. It is analogous to resistance in an electric circuit. The lower the reluctance, the easier it is for magnetic flux to flow.

The path of the magnetic flux in a transformer should have low reluctance so that the magnetic flux can flow easily and produce a strong magnetic field. This is necessary for the transformer to operate efficiently.

The other options are incorrect.

• High reactance would cause the magnetic flux to flow more slowly, which would reduce the efficiency of the transformer.
• High resistance would cause the magnetic flux to be dissipated as heat, which would also reduce the efficiency of the transformer.
• Low resistance would not affect the flow of magnetic flux, but it would not be necessary for the transformer to operate efficiently.