Question

The core of any transformer is laminated in order to:
A. Reduce the energy loss because of the eddy currents
B. Make it light weight
C. Make it robust and strong
D. Increase the secondary voltage

Answer 1

Hint: If there is a variation in flux linked with the core of a transformer, which will induce an electromotive force in the core which in turns develops a circulating current referred to as eddy current. And these losses can produce a loss that is given as eddy current losses. These details will help you to solve this question.

Complete step by step answer:
Eddy currents are defined as the loops of electrical current induced within a conductor due to the variation in magnetic field in a conductor. The resistance of the core should be made high in order to reduce the eddy current loss. Generally in transformers, some thin sheets of steel are insulated in the core from each other by a thin layer of varnish. The huge resistances between the sheets will control the eddy currents into the thin sheets. Therefore by giving the core with thin laminations which are parallel to the magnetic field with an insulation between them will decrease the eddy currents and therefore the energy loss due to the eddy current will also get reduced.

Note:
The eddy current is explained by Faraday's law of induction. Faraday’s law of induction says that any variation in the nature of a coil of wire will result in a voltage to be induced in the coil, without considering how the magnetic change is developed. Therefore when a motor core is rotated in a magnetic field, a voltage or electro motive force gets induced in the coils.