Important Questions for Class 7 Chapter 3 - Fibre to Fabric

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Important questions based on NCERT syllabus for Chapter 3 - Fibre to Fabric:

Question-1: Discuss the process of obtaining silk.

Solution: For obtaining silk, moths are reared and their cocoons are collected to get silk threads. The cocoons are boiled to separate out silk fibres from cocoon. Threads obtain from the cocoon spun into silk threads, which are woven into silk cloth by weavers. The process of taking out threads from the cocoon for use as silk is called reeling the silk.

Question-2: Why do wool yielding animals have a thick coat of hair?

Solution: The wool yielding animals have a lot of hair and it helps them to trap lot of air. Air is a poor conductor of heat and keeps these animals warm during winter by not letting the body heat escape.

Question-3: Explain the process of obtaining silk from the silk moth.

Solution: The processing of fibres into wool involves the following steps:
Step I: Shearing:- At first hair are removed using shearing machine
Step II: scouring:- Hair is washed in tanks to remove grease, dust and dirt. This process is called scouring.
Step III: After scouring, sorting of hair is done on the basic of different textures
Step IV: The small fluffy fibres, called burrs, are picked out from the hair
Step V: The fibres then dyed in various colours, according to choice
Step VI: The coloured fibres are straightened, combed and rolled into yarn