Question

Given below are two statements:
Assertion (A): Cellulosic textiles can be permanently heat set.
Reason (R): Heat setting can be performed on thermoplastic polymers which when heated under strictly controlled temperatures soften and can be made to take any shape. When cooled, they will retain the desired shape of configuration.
In the light of the above statements, choose the most appropriate answer:

• A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
• B. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
• C. (A) is correct but (R) is not correct
• D. (A) is not correct but (R) is correct

Hint:

Only thermoplastic fibres can be permanently heat set; cellulosic fibres like cotton cannot.

Answer 1

The Correct Option is D

Step 1: Understanding the Question:

• We must judge the Assertion (A) about heat setting of cellulosic textiles and the Reason (R) about thermoplastic polymers.

Step 2: Detailed Explanation:

• Assertion (A): Cellulosic fibres such as cotton and linen are not thermoplastic. They do not soften on heating and cannot be permanently heat set, so (A) is not correct.

• Reason (R): Thermoplastic fibres soften under controlled heat, take a new shape, and keep it on cooling. This is the principle of heat setting, so (R) is correct.

Step 3: Final Answer:
(A) is not correct but (R) is correct. The correct option is (D).