Question

Silicon steel is widely used for-
1. Connecting rods 
2. Transformers
3. Cutting tools 
4. Motor crank shafts

Answer 1

Correct Answer - Option 2 : Transformers

Concept:

• Silicon steel is an important soft magnetic material is used nowadays. 
• It is a ferritic alloy of iron and silicon that has magnetic properties which makes it useful in the electrical industry (generators, motors, and transformers).
• In Si-steel, the Si is added in Fe up to 5%
• The effects of adding silicon are:
  • Permeability increases
  • Resistivity increases
  • Hysteresis losses decrease
• As Si is semi-conductor and Fe is a conductor so resistivity ρFe < ρSi .
• As resistivity increases the eddy current loss decreases. Hence silicon steel is used in electrical machines.
• The earlier magnetic material used was iron but it contains many impurities. So silicon is added to steel to improve its soundness, i.e. free from defects, decays, or damages.