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GK QUESTION#3565

Assertion (A): Appropriate vulcanisation improves rubber’s elastic recovery and durability.

Reason (R): Sulphur forms cross-links between rubber polymer chains, improving mechanical properties.

  1. ABoth A and R are true, and R is the correct explanation of ACorrect answer
  2. BBoth A and R are true, but R is not the correct explanation of A
  3. CA is true, but R is false
  4. DA is false, but R is true
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Answer

A. Both A and R are true, and R is the correct explanation of A

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Explanation

Appropriate sulphur vulcanisation creates cross-links between rubber polymer chains. These links limit permanent chain slippage and improve elastic recovery, strength and durability compared with untreated rubber. Both the assertion and the reason are true, and the cross-links explain the improvement; excessive cross-linking can produce a harder material.

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