Question

(a) Cast iron is very hard and brittle because of higher carbon content.
(b) Iron obtained from the blast surface is known as pig iron.
(c) The carbon content of wrought iron is the least.
(d) The melting point of cast iron is higher than that of wrought iron.
Which of the following regarding the above statements is correct?
(A) a, b and c
(B) c and d
(C) only b
(D) only d

Answer 1

Hint: In the above question, we are asked to select the correct statements given about cast iron, pig iron and wrought iron. These iron differ from each other in their carbon content. Higher the carbon content, more brittle is the type of iron.

Complete Step by step solution
Iron is pure and brittle metal. In ancient times, iron was used as a weapon.
Pig iron has a high carbon content and acts as an intermediate product for making steel. It is the product of melting iron ore in a blast furnace.
Wrought iron is iron with a low carbon content, it was used in place of steel before steel became available but is now used in the steel making process. It is obtained by smelting pig iron.
Cast iron has the highest carbon content that has been shaped by being poured into a cast. It is used in pots and pans etc. It is made from molten pig iron. Because of its low melting point, it is used in pipes and machines.
We can now conclude that cast iron is very hard and brittle because of higher carbon content. Iron obtained from the blast surface is known as pig iron. The carbon content of wrought iron is the least. And the melting point of cast iron is lower than that of wrought iron. Hence, option a, b and c are correct.
So, the correct option is option A.

Note
Since, cast iron is comparatively brittle, it is not suitable for purposes where a sharp edge or flexibility is required. It is strong under compression, but not under tension. Wrought iron, like most other kinds of iron and indeed like most metals in general, is strong in tension, and also tough and resistant to fracturing. The relationship between cast and wrought iron is analogous to wood and stone.