Question

The main difference between cast iron and pig iron is that:

• A. cast iron is purest from iron while pig iron is impure
• B. cast iron has lower carbon content (3%) as compared to pig iron (4%) and is extremely hard and brittle
• C. pig iron contains many impurities like $S,P,Si$ and $Mn$ while cast iron does not contain any impurity and can be cast into any shape
• D. cast iron is soft and malleable while pig iron is extremely hard and brittle

Answer 1

Answer: (B)

cast iron has lower carbon content (3%) as compared to pig iron (4%) and is extremely hard and brittle

The iron obtained from Blast furnace contains about 4% carbon and many impurities in the smaller amount (e.g., $S,P,Si,Mn$). This is known as pig iron. It can be moulded into variety of shapes.
Cast iron is different from pig iron and is made by melting pig iron with scrap iron and coke using hot air blast. It has slightly lower carbon content (about 3%) and is extremely hard and brittle.
Hence, option $B$ is the correct answer.