UPSC Prelims 1998 · General Studies
Question 106: Science and Technology
Consider the following statements: Coke is one of the materials of the charge added to blast furnace for the production of steel/iron. Its function is to I. Act as a reducing agent. II. Remove silica associated with the iron ore. III. Function as fuel, to supply heat. IV. Act as an oxidizing agent. Of these statements:
AnswerThe answer is (c).
In a blast furnace coke burns to give the heat that the furnace needs and forms carbon monoxide, the gas that reduces iron oxide to iron. Silica in the ore is removed by the limestone flux, which forms slag, not by coke. Coke is a reducing agent, not an oxidising agent. So I and III are correct.
- I. Coke, as carbon and carbon monoxide, reduces the iron ore.
- II. Silica is removed by limestone flux as slag, not by coke.
- III. Coke burns to supply the heat.
- IV. Coke is a reducing agent, not an oxidising one.
Why each option is right or wrong
- (a) II is wrong: silica is removed by limestone flux.
- (b) II and IV are both wrong.
- (c) Right: coke is a reducing agent and the fuel.
- (d) IV is wrong: coke is not an oxidising agent.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 1998, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.