**Introduction:**
In a transformer, the core is an essential component that is responsible for transferring the magnetic flux from the primary winding to the secondary winding. The core is typically made of ferromagnetic material, which exhibits both magnetic and magnetostrictive properties. Magnetostriction is the phenomenon in which a material changes its shape or dimensions when magnetized.

**Explanation:**
When a ferromagnetic core is used in a transformer, it experiences magnetostriction due to the varying magnetic field. Magnetostriction causes a change in the dimensions of the core, leading to mechanical stress and vibration. This vibration can produce an audible noise known as transformer hum. To minimize these effects, laminated or grain-oriented ferromagnetic cores are commonly used.

If a paramagnetic core is used in place of the ferromagnetic core, the magnetostriction phenomenon will be vanished. This is because paramagnetic materials do not exhibit magnetostrictive properties. Unlike ferromagnetic materials, paramagnetic materials do not undergo significant dimensional changes when subjected to a magnetic field.

**Reasoning:**
The magnetostrictive properties of a material are primarily determined by its crystal structure and the presence of magnetic domains. Ferromagnetic materials have a well-defined crystal structure and possess magnetic domains, which contribute to magnetostriction. In contrast, paramagnetic materials have a random orientation of magnetic moments and lack magnetic domains, resulting in the absence of magnetostriction.

**Conclusion:**
In summary, when a para magnetic core is used in place of the ferromagnetic core in a transformer, the magnetostriction phenomenon will be vanished. This is because paramagnetic materials do not exhibit magnetostrictive properties due to their random magnetic moments and lack of magnetic domains.