Question

Determine the correctness or otherwise of the following Assertion [a] and Reason [r].
[a]: Para-aramid fibres have better mechanical properties as compared to meta-aramid fibres.
[r]: The chemical structure of para-aramid fibres allows them to pack closely.

• A. Both [a] and [r] are true and [r] is the correct reason for [a]
• B. Both [a] and [r] are true and [r] is not the correct reason for [a]
• C. Both [a] and [r] are false
• D. [a] is true but [r] is false

Hint:

Para-aramid fibres have superior mechanical properties due to their rigid molecular structure, which allows for better alignment and packing of the polymer chains. This results in better performance in applications requiring strength and durability.

Answer 1

The Correct Option is A

Step 1: Analyzing the Assertion [a].
Para-aramid fibres, such as Kevlar, have better mechanical properties compared to meta-aramid fibres, like Nomex. Para-aramid fibres are stronger, more resistant to heat, and have superior tensile strength. This is a well-known fact in the field of fibre materials. Step 2: Understanding the Reason [r].
The reason states that the chemical structure of para-aramid fibres allows them to pack closely. This is true. The para-aramid fibres have a more rigid, linear structure that allows the polymer chains to align more closely with each other. This close packing contributes to their enhanced mechanical properties, such as higher tensile strength. Step 3: Conclusion.
Both the assertion and the reason are true. Furthermore, the reason directly explains the enhanced mechanical properties of para-aramid fibres, which supports the assertion. Thus, the correct answer is (1).