Class 8 lesson 3 important question

Q1: A synthetic fibre is a chain of small _____________ joined together.
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Q2: Give examples of some natural and man- made fibres.
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Q3: Define synthetic fibres.
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Q4: Define polymer
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Q5: Cellulose is made up of large number of___________________ units.
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Q6: What is artificial silk?
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Q7: Name the source of rayon.
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Q8: Define nylon fibre.
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Q9: Write down few properties of nylon.
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Q10: Name some articles used in our day to day life made from nylon.
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Q11: Polyester fabrics do not get__________________ easily.
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Q12: Give example of polyesters.
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Q13: Tick the correct answer
Acrylic is used to make

• Penicillin
• Alcohol
• Nitrate
• None of these

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Q14: What happens when synthetic fibres catch fire?
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Q15: Define petrochemicals.
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Q16: State few properties of plastics.
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Q17: Name some articles made from plastics
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Q18: Give examples of thermoplastics.
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Q19: Give examples of thermosetting plastics.
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Q20: Which one is good conductor of electricity: Bakelite or melamine?
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Q21: Why we prefer plastic containers for storage of items like water, milk, pickles, dry food?
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Q22: Plastics are poor conductor of ______________ and ____________________.
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Q23: What is Teflon?
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Q24: What do you mean by fire proof plastics?
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Q25: What do you mean by biodegradable?
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Q26: What do you mean by non-biodegradable?
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Q27: Paper is biodegradable or non- biodegradable?
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Q28: Why should we use a cotton carry bag or jute bag while going to market?
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Q29: Why plastic articles are available in all shape and size?
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Q30: Can all plastic articles be bent easily?
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Q31: Illustrate various uses of thermoplastic andthermosetting plastics.
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Q32: Name the fibre having properties similar to that of silk.
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Q33: Tick the right answer
Nylon fibres are used for making

• Ropes for rock climbing
• Parachutes
• Socks
• All of the above