The soft-iron is a suitable material for making an electromagnet. This is because soft-iron has
The soft-iron is a suitable material for making an electromagnet. This is because soft-iron has
low coercivity and high retentivity.
low coercivity and low permeability.
high permeability and low retentivity.
high permeability and high retentivity.
Solution
Electromagnets are made of soft iron because of its high permeability and low retentivity. High permeability means that the core provides complete linkage of magnetic flux of the primary coil to the secondary coil. The determination of the magnetism left in the material after the removal of the magnetizing field is known as retentivity. The required condition for the operation of electromagnets is the fast reversal of polarity, so high retentivity is undesirable. So, soft iron core has high permeability and low retentivity.