NCERT Solutions for Class 8 Science Chapter 3| Download in PDF
NCERT Solutions for Class 8 Science Chapter 3 – Artificial Fibres and Plastics by Jagran Josh will enable you discover correct and easy solutions to all questions given in the chapter.
We’re offering right here the perfect NCERT Solutions for Class 8 Science Chapter 3 – Artificial Fibres and Plastics. College students can learn in addition to obtain these NCERT Solutions and discuss with them for making easy preparations for their Science examination. We have now supplied right here the NCERT Solutions for Science chapter 3 of the most recent NCERT E book for Class 8 Science. Verify probably the most correct NCERT Solutions to clear the ideas and do properly in the topic.
NCERT Solutions for Class 8 Science Chapter 3 – Artificial Fibres and Plastics:
1. Clarify why some fibres are referred to as artificial.
Some fibres are referred to as artificial fibres as a result of they’re made by man utilizing various kinds of chemical substances.
2. Mark the right reply.
Rayon is totally different from artificial fibres as a result of
(a) it has a silk-like look.
(b) it’s obtained from wooden pulp.
(c) its fibres can be woven like these of pure fibres..
Reply: (b) it’s obtained from wooden pulp.
3. Fill in the blanks with acceptable phrases.
(a) Artificial fibres are additionally referred to as ________or _________fibres.
(b) Artificial fibres are synthesised from uncooked supplies referred to as ________.
(c) Like artificial fibres, plastic can also be a _________.
(a) Artificial fibres are additionally referred to as synthetic or man-made fibres.
(b) Artificial fibres are synthesised from uncooked supplies referred to as petrochemicals.
(c) Like artificial fibres, plastic can also be a polymer.
4. Give examples which point out that nylon fibres are very robust.
Examples which point out that nylon fibres are very robust are:
→ Nylon is used in making ropes for mountaineering.
→ Nylon is used in making parachutes.
→ Nylon is used in making seat belts.
5. Clarify why plastic containers are favoured for storing meals.
Plastic containers are favoured for storing meals due their following properties:
→ The plastics are non-reactive so they don’t get corroded.
→ The plastics don’t react with the meals saved in them.
→ They’re gentle weight and have good energy.
→ They’re low cost and simple to deal with.
6. Clarify the distinction between thermoplastic and thermosetting plastics.
Distinction between thermoplastic and thermosetting plastics:
The plastic which will get softened on heating and will be bent simply is called thermoplastic.
The plastic that can’t be softened on heating is called thermosetting plastic. It might break when pressured to bend.
It may be molded and reshaped simply.
It can’t be molded and reshaped simply.
Examples: Polythene and PVC
Examples: Bakelite and Melamine
7. Clarify why the next are product of thermosetting plastics.
(a) Saucepan handles
(b) Electrical plugs/switches/plug boards
(a) The saucepan handles are product of thermosetting plastics as a result of they’re unhealthy conductors of warmth. So they don’t get heated up whereas cooking and will be dealt with simply. Along with this, thermosetting plastics don’t get softened on heating.
(b) Electrical plugs, switches and plug-boards are made up of thermosetting plastics as a result of they’re unhealthy conductors of electrical energy. So, they don’t permit the electrical present to cross by means of them are thus secure to the touch.
8. Categorize the supplies of the next merchandise into ‘will be recycled’ and ‘can’t be recycled’.
Phone devices, plastic toys, cooker handles, carry baggage, ball level pens, plastic bowls, plastic masking on electrical wires, plastic chairs, electrical switches.
will be recycled
can’t be recycled
plastic toys, carry baggage, plastic bowls, plastic masking on electrical wires, plastic chairs
phone devices, cooker handles, ball level pens electrical switches
9. Rana desires to purchase shirts for summer time. Ought to he purchase cotton shirts or shirts constructed from artificial materials? Advise Rana, giving your motive.
Rana can buy shirts constructed from cotton as a result of it’s a good absorber of water. Due to this fact, it may well soak the sweat popping out of our physique and provides reduction from excessive warmth.
10.Give examples to indicate that plastics are non-corrosive in nature.
Some examples to indicate that plastics are non-corrosive in nature are:
→ Plastics don’t react with water and air.
→ They do react with the chemical substances saved in the plastic bottles.
→ Plastics don’t react with the meals gadgets saved in them.
11.Ought to the deal with and bristles of a tooth brush be product of the identical materials? Clarify your reply.
No, the deal with and bristles of a tooth brush shouldn’t be product of the identical supplies. The deal with of a toothbrush must be the handles must be made up of onerous and robust materials in order that it may give a agency grip. Then again, the bristles must be made up of sentimental and versatile materials in order that they don’t harm our gums.
12. ‘Keep away from plastics so far as doable’. Touch upon this recommendation.
Plastics are non-biodegradable supplies which implies they don’t get decomposed. They result in air air pollution as on burning they launch toxic gases into the environment. Additionally, the plastic baggage thrown in rubbish if swallowed by animals can choke their respiratory system and even result in their dying. Plastics baggage thrown carelessly also can trigger clogging of the drains.
13. Match the phrases of column A appropriately with the phrases given in column B.
(a) Ready by utilizing wooden pulp
(b) Used for making parachutes and stockings
(c) Used to make non-stick cookware
(d) Materials don’t wrinkle simply
(a) Materials don’t wrinkle simply
(b) Used to make non-stick cookware
(c) Ready by utilizing wooden pulp
(d) Used for making parachutes and stockings
14. ‘Manufacturing artificial fibres is definitely serving to conservation of forests’. Remark.
Pure fibres like cotton, silk, wool and jute are obtained from crops and animals, whereas artificial fibres are obtained from petrochemicals. Thus, the manufacturing of artificial fibres has diminished the chopping of bushes or searching of animals. On this manner manufacturing artificial fibres is definitely serving to conservation forests.
15. Describe an exercise to indicate that thermoplastic is a poor conductor of electrical energy.
The next exercise can present that thermoplastic is a poor conductor of electrical energy:
We’ll design a circuit to indicate that thermoplastics are poor conductors of electrical energy.
→ For this exercise, take a bulb, wires, a battery, a bit of steel, and a plastic pipe.
→ Make two circuits – one with the steel and different with the plastic pipe as proven in the next diagrams.
→ After switching on the circuit, you’ll observe that the bulb in the circuit with steel begins glowing whereas in the opposite circuit with plastic pipe bulb doesn’t glow.
→ This proves that the plastic pipe which is a thermoplastic is a poor conductor of electrical energy.
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