Core of transformer is made up of

Explanation

Soft iron is used to make the core of a transformer because :
1. It has high permeability. As a result magnetic field lines crowd through the core and linkage of magnetic flux between the two coils will also be more.
2. It has narrow hysteresis loop and hence during magnetisation and demagnetisation, loss of energy will be equal.
The core of a transformer is laminated to minimise the loss of energy due to eddy currents.