Class 7 Science Question Answers - Fibre to Fabric

Short Answer Type Questions

Q1: What are natural fibres? Give example.

Ans: The fibres of some fabric are obtained from plants and animals. These are called natural fibres. For example: cotton, jute, silk etc are natural fibres.

Cotton

Q2: Which of these are natural fibres –

Silk, Nylon, Wool, Polyester, Cotton

Ans: Silk, Wool and Cotton, all are natural fibres.

Q3: Write the difference between natural and synthetic fibres.

Ans: The fibres of some fabric are obtained from plants and animals. These are called natural fibres. For example-cotton, jute, silk etc. The fibres that are made from chemical substances are called synthetic fibres. For example-nylon, polyester etc.

Q4: What is ginning?

Ans: Cotton fibres are separated from the seeds by combing. This process is known as ginning. Machines are also now used for ginning.

Q5: Define weaving.

Ans: The process of arranging two sets of yarns together to make a fabric is called weaving. Weaving of fabric is done on looms.

Q6: What happens after maturing of fruit of cotton plant (cotton bolls)?

Ans: After maturing, the bolls burst open and seeds covered with cotton fibres can be seen. Then the cotton can be picked.

Q7: How is spinning done on large scale?

Ans: Spinning is done on large scale with the help of spinning machines. After spinning yarns are used for making fabric.

Q8: Where does cotton wool come from?

Ans: Cotton wool is grown in fields. Plants are grown at places having black soil and warm climate.

Q9: What will happen if we pull the yarn from torn pair of socks? Why so?

Ans: A single yarn gets pulled out continuously as the fabric gets unravelled. It is because they are made of knitted fabric.

Q10: What are looms?

Ans: Looms are those on which weaving of fabric is done. They are either hand operated or power operated.

Q11: Choose the correct option-
1. Cotton is obtained from ____________of plant. (seed/stem)
2. Nylon is ____________fibre.(natural/synthetic)
3. Jute is obtained from ____________. (plant/animal)
Ans:
a) Seed.
b) Synthetic.
c) Plant.

Q12: Match the correct option-

Ans:  
Silk- Animal fibre
Charkha - Spinning
Polyester - Synthetic Fibre
Jute - Plant Fibre

Long Answer Type Questions

Ans: The process of making yarn from fibres is called spinning. In this process, fibres from a mass of cotton wool are drawn out and twisted. This brings the fibres together to form a yarn. A device used for spinning is charkha.