Exercises
Fill in the blanks with suitable words.
1. Fibres are classified as natural and synthetic.
2. Fibres obtained from animals are called animal fibres.
3. Nylon and polyester are synthetic fibres
4. To make fabrics, fibres are first converted to yarn.
5. The process of drawing yarn from fibres is called spinning.
6. In knitting , single yarn used to make a fabric.
B. Multiple choice questions
1. Jute is a/an
ans. plant fibre
2. Yarns are made of
ans. Fibres
3. Cotton grows best in
ans. black soil
4. Which of these is not a fibre
ans. leather
5. Weaving is done on special machines called
ans. looms
C. Very short answer questions. (ONE WORD)
1. Name of plant fibre. Jute
2. Name of one animal fibre. Wool
3. Name one synthetic fibre. Nylon
4. Process of rotting stems of jute plants. Retting
5. Plant from which linen is obtained. Flax plant
6. Stronger fibre are natural or synthetic. Synthetic
7. From which part of the plant cotton is obtained. Fruit Part
D. Short answer questions.
1. Define
(a) Ginning:-
The process of separating cotton fibres from seeds is called ginning. After ginning, bales of cotton are made.
(b)Retting:-
The process of separating jute fibres by rotting the stem of jute plants is called retting. In the process, the stem are tied into bundles and immersed in water for a few days. The stems begin to rot.
(c)Spinning:-
The process of making yarn(thread) from the fibres by twisting is called spinning. It is one of the most ancient art. In this process, fibres from a mass of cotton wool are drawn out and twisted.
(d) Weaving
The process of making cloth by crossing two sets of threads over and under each other. This is known as weaving. Weavers may use threads (yarn) spun from natural fibres but artificial fibres are also popular. There are three basic kinds of weave -plain weave, the twill weave and the satin weave. It is done on a machine called looms.
2. Define fibres. Name different types of natural fibres used to make cloth.
ans. Fibre is a hair-like strand of a substance that is spun into yarn. Cotton, flax,jute silk and wool are natural fibres mostly used in clothing.
3. Differentiate between fibre and yarn.
ans.Fibre is a hair-like strand of a substance that is spun into yarn.
Yarn is a combination of several fibres twisted together to knit or weave a fibric.
4. What are synthetic fibres? Give two examples.
ans. Synthetic fibres are made by man from chemicals. Nylon, rayon are the two example of fibres.
5. Write properties of silk fibres.
ans. Silk is one of the most strongest fibres. It loses up its strength by 20% when it is wet. It has a smooth, soft texture which is slippery unlike many synthetic fibres.
6. How do woollen clothes keep us warm in winter.
and. The woollen clothes does not allow the heat to escape, and prevent air to pass in. That's how woollen clothes keep us warm in winter.
E. Long answer questions.
1. Explain how cotton fibres are obtained form cotton plant.
ans. After harvesting by handpicking , cotton are removed from seed. The process of separating cotton fibres from seeds is called ginning. After ginning, bales of cotton are made. Next process is called spinning. The process of making yarn(thread) from the fibres by twisting is called spinning.
2. Write short notes on the uses of jute and flax.
ans. Jute: It is one of the cheapest natural fibre. Jute is mainly used to make clothes for wrapping bales of raw cotton and to make sacks and coarse cloth. It is also used in curtains, chair covering etc.In India it is grown in West Bengal and Assam.
Flax:-Flax is mainly grown for seeds. It can be ground into a meal and turned into linseed oil. It is used as nutritional supplement and as an ingredients of wood finishing products. Flax fibre are grown to make linen.
3. How are fibres classified? Explain their characteristics.
ans. Fibres are classified into two categories.Natural and Synthetic ( Man Made)
Characteristics of Natural Fibres:
- They are soft and delicate.
- They are long and flexible
- They can easily be made thread.
Characteristics of Synthetic Fibres
- They are stronger than natural fibres.
- They are manufactured from chemicals.
- They are durable
- They are dried up in less time.
4. Explain the process of making yarn from fibre.
ans. Yarns are made up of thin strands called fibres. They obtained by a process called spinning. In this process, fibres from a mass of cotton wool are drawn out and twisted.
5. How is weaving different from knitting?
ans. Weaving is the process of making cloth by crossing two sets of threads over and under each other while knitting is a method of making fabric by looping yarn around each other using two or more knitting needles or knitting machine.
6. How is jute fibre made from jute plants?
ans. The stems of the jute plant tied into bundles and immersed in water for a few days. The stems begin to rot. This process is called retting. The fibres are then separated and washed in clear running water. Then they are hung up or spread on thatched roofs to dry.
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For the notes of the previous chapter of science, click the links given below
Sorting Materials into Groups, Science Class VI.
Separation of Substances Science Class VI
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