Question
Physics Question on Alternating current
Core of a transformer is made up of:
A
soft iron
B
steel
C
iron
D
alnico
Answer
soft iron
Explanation
Solution
Soft iron is used for making transformer cores. In these cases the material goes through complete cycles of magnetisation continuously. The material must therefore have a low hysteresis loss to have less dissipation of energy and hence a small heating of the material (otherwise the insulation of the windings may break), a high permeability (to obtain a large flux density at low field) and a high specific resistance (to reduce eddy current loses). These requirements are fulfilled by soft iron. Hence compared to steel iron and alnico soft iron is preferred for use as core of a transformer.