Question

13. (a) Why do we say that “Rayon is not completely an artificial fibre”?
(b) Name the synthetic fibre which appears to resemble wool.
(a) हम क्यों कहते हैं कि 'रेयॉन पूर्णतयाः कृत्रिम फाइबर नहीं है?
(b) उस कृत्रिम फाइबर का नाम लिखिये जो ऊन से मिलता हुआ लगता है।
(2)
14. Give two reasons to justify that it is not advisable to wear synthetic clothes
while working in the kitchen.
"कृत्रिम कपड़े पहनकर रसोई में कार्य करना उचित नहीं है।" दो कारण बताइये जो उपरोक्त कथन
के औचित्य को साबित करते हैं।
(2)
15. State two factors on which the process of electrolysis depends.
। विद्युत अपघटन (इलैक्ट्रोलीज) को प्रभावित करने वाले दो कारकों के नाम लिखिये।
(2)
16. (a) Name the structure, present in birds that helps them to produce their
characteristic sounds.
(b) How do frogs produce their croaking sounds ?
(a) उस संरचना का नाम लिखिये जिसकी सहायता से पक्षी अपनी-अपनी विशिष्ट ध्वनियाँ निकालते हैं​

Answer 1

Answer:

Rayon is a semi-synthetic fibre also called man- made fibre . Rayon is a regenerated cellulosic fibre. Rayon is obtained by chemical reaction of carbon disulphide and NaOH with (Natural Cellulose)wood pulp. Cellulose is a natural polymer that is why it is known as Semi-synthetic /artificial fibre.