Consider the following:

1. Carbon fibres are used in the manufacture of components used in automobiles and aircrafts.

2. Carbon fibres once used cannot be recycled. 

Which of the statements given above is fare correct? 

(a) 1 only 

(b) 2 only 

(c) Both 1 and 2 

(d) Neither 1 nor 2

Ans: a

Explanation:

The Carbon fibres are composed of carbonised polymers, which are lengthy chains of molecules joined by strong bonds between carbon atoms. A precursor material is heated to around 3,000°C in an environment of inert gases to create the fibres. The most commonly used precursor is polyacrylonitrile (PAN), which is produced by the petrochemicals industry. Alternatively, pitch made from coal tar is occasionally utilised. The fibres are spun into yarns, molded into tapes, or threaded into bobbins once they have carbonised. They can also be woven into fabric sheets, depending on the intended use.

Because it is incredibly strong and lightweight, carbon fibre is appealing. Being the strongest fibre, they have 10 times the strength of steel and eight times the strength of aluminum. The carbon fibre is also five times lighter than steel and half the weight, or less, of aluminum. Nor does it corrode. Therefore, they are used in aircrafts and automobiles.

Hence, statement 1 is correct.

On their own, carbon fibres are brittle and can break easily. But their strength comes in tension (they resist being pulled apart). So, the fibres need to be aligned in such a way to impart their strength by distributing loads throughout a structure.

Carbon fibres can be made from manufacturing offcuts or recycled material and can themselves be recycled.

Hence, statement 2 is incorrect.

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