Correct Option
The correct option is Coke : Used in manufacturing steel
Explanation
Coal is processed in industries to obtain useful products such as coke, coal tar, and coal gas. These by-products, along with petroleum derivatives like bitumen, have distinct industrial and commercial applications based on their chemical and physical properties.
Option Analysis
- Option (a) is Correct: Coke is a tough, porous, and black substance which is an almost pure form of carbon. It is extensively used in the manufacture of steel and in the extraction of many metals due to its ability to act as a reducing agent.
- Option (b) is Incorrect: Coal Tar is a thick black liquid with an unpleasant smell. It is used as a starting material for manufacturing synthetic dyes, drugs, explosives, perfumes, plastics, and paints. It is not used for street lighting; Coal Gas was historically used for that purpose.
- Option (c) is Incorrect: Coal Gas is obtained during the processing of coal to get coke. It is primarily used as a fuel in industries. It is not used for metalling roads.
- Option (d) is Incorrect: Bitumen is a petroleum product, not a coal derivative. It is currently used in place of coal tar for metalling (surfacing) roads. It is not used for the extraction of metals.
Key Takeaway
Coke is essential for steel manufacturing and metal extraction. Bitumen (from petroleum) is used for road surfacing. Coal Gas is used as fuel, and Coal Tar is a raw material for various chemical industries.