Question

Why is the core of a transformer laminated?

Answer 1

The core is not designed to have any currents flow through it. It is, however, a conducting loop that experiences a changing magnetic field, it will, therefore, have small current induced in it. These are called eddy currents.

The core is laminated to reduce these currents to a minimum as they interfere with the efficient transfer of energy from the primary coil to secondary coil.