Long question of class 7th science chapter 3FIBER TO FABRIC
SUBHAM TUTORIAL
Fiber to fabric
Question2: Describe the life cycle of silk worm ?
Answer:
(i) The life history of a silk moth starts when a female silk moth lays eggs.
(ii) The larvae or caterpillars hatched from the eggs of the silk moth. These silkworms feed on fresh mulberry leaves the silkworm grows in size and then becomes a pupa.
(iii) In the pupa stage, it weaves a net to hold itself. It then swings its head from side to side, secreting a fibre that hardens on contact with air.
(iv)The fibre is made of a protein and becomes the silk fibre.
(v) The caterpillar covers itself completely with silk fibre and turns into a pupa, this covering is known as the cocoon.
(vi)The moth continues to develop within the cocoon. The silk thread or yarn is obtained from the silk moth’s cocoon.
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Fiber to fabric
Question no.1
Explain the process involved in obtaining wool.
Answer:
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.
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.
Question2: Describe the life cycle of silk worm ?
Answer:
(i) The life history of a silk moth starts when a female silk moth lays eggs.
(ii) The larvae or caterpillars hatched from the eggs of the silk moth. These silkworms feed on fresh mulberry leaves the silkworm grows in size and then becomes a pupa.
(iii) In the pupa stage, it weaves a net to hold itself. It then swings its head from side to side, secreting a fibre that hardens on contact with air.
(iv)The fibre is made of a protein and becomes the silk fibre.
(v) The caterpillar covers itself completely with silk fibre and turns into a pupa, this covering is known as the cocoon.
(vi)The moth continues to develop within the cocoon. The silk thread or yarn is obtained from the silk moth’s cocoon.
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where is mcq of fibre to fabric ( class 7th ,5th chapter )
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