Free IICRC WRT Basic Questions and Answers — Questions and Answers
Question 1: These fibres come from plants and animals
- Protein
- Cotton
- Wool
- Cellulosic
- Natural fibers (Correct answer)
Correct answer: Natural fibers
Natural fibers are broadly defined as fibers derived directly from natural sources, specifically plants (like cotton, linen) and animals (like wool, silk). This category distinguishes them from synthetic or man-made fibers. Therefore, 'natural fibers' is the overarching term that encompasses both plant and animal-derived fibers.
Question 2: Natural fibres require longer drying times because they are?
- Adsorbent
- Moisture resistant
- Tufted
- Hydrophyllic
- Absorbent (Correct answer)
Correct answer: Absorbent
Natural fibers, particularly cellulosic ones like cotton and linen, are highly absorbent due to their molecular structure, meaning they readily take in and hold onto moisture. This characteristic causes them to retain water for longer periods, thus requiring extended drying times compared to less absorbent synthetic fibers. Their absorbent nature directly impacts drying efficiency.
Question 3: Fibres that come from plants are called?
- Cellulosic (Correct answer)
- Synthetic
- Cuticle
- Jute
- Protein
Correct answer: Cellulosic
Plant-based fibers, such as cotton, linen, jute, and hemp, are primarily composed of cellulose, a complex carbohydrate. Therefore, they are collectively referred to as cellulosic fibers. This term specifically categorizes fibers derived from plant sources, distinguishing them from protein (animal) or synthetic fibers.
Question 4: Fibres that are taken from animals or animal by-products are called?
- Wool
- Flame resistant
- Tri-lobial
- Protein (Correct answer)
- Adsorbent
Correct answer: Protein
Animal fibers, such as wool, silk, and cashmere, are primarily composed of proteins. This chemical composition gives them unique properties and distinguishes them from plant-based (cellulosic) or synthetic fibers. Therefore, 'protein fibers' is the correct classification for fibers derived from animals or animal by-products.
Question 5: Protein fibres are dissolved in a 5.25% solution of?
- Alcohol
- Bleach (Correct answer)
- Lye
- Asorbic acid
- Formic acid
Correct answer: Bleach
A 5.25% solution of sodium hypochlorite, commonly known as household bleach, is a strong oxidizing agent that can dissolve protein fibers like wool or silk. This chemical test is often used in fiber identification to distinguish protein fibers from cellulosic or synthetic fibers, which typically resist dissolution in bleach. This reaction is a key characteristic of protein fibers.
Free IICRC WRT Basic Questions and Answers
These fibres come from plants and animals