Telangana SCERT Class 8 Physical Science Chapter 3 Synthetic fibres and Plastics Solution

Telangana SCERT Class 8 Physical Science Chapter 3 Solution – Synthetic fibres and Plastics. Here in this post we provides Class 8 Physical Science Synthetic fibres and Plastics Telangana State Board Solution.  Telangana State Board English Class VIII Medium Students can download this Solution to Solve out Improve Your Learning Questions and Answers.

Telanagana State Board Class 8 Physical Science Chapter 3 Synthetic fibres and Plastics Solution:

 (1) Why some fibres are called Synthetic? Explain.

Ans: – Natural fibres, synthetic, fibres are made from petroleum based chemicals or petro chemicals. Petrochemicals are subjected to various chemical processed to obtain synthetic fibre. For these reason they are called synthetic fibres or artificial fibres. These fibres are called as man made from fibres and also it does not made from natural substances instead they are made from chemicals.

(2) List out the objects made up of Acrylic.

Ans: – It is used in knitted apparels such as –

Fleece, socks, sportswear and sweaters.

It is also used in craft yarns, upholstery fabric, carpets, luggage awnings and vehicle covers.

House hols items like spoons, cups, boxes, pen stands etc.

(3) Draw and explain the diagram of Universal recycling symbol.

Ans: –

To identify the plastic, look at the recycling icon, the chasing arrows. Inside identifies the polymer. When the number is omitted as seen in this figure, the symbol is known as the Universal Recycling symbol, indicating generic recyclable materials.

(4) What are thermosetting plastics? Give two examples.

Ans: – Thermo setting plastics are simply plastics, when moulded into a shape and allowed to cool down, will remain in moulded from and will not change their shape. When heated again they will char or burn. Thermosetting plastics are synthetic materials which gain strength during moulding by heating, but cannot be remoulded or reheated after their initial heat, moulding.

So thermosetting, plastic are not remould able.

Examples are –

Polyester rosin, PVC.

(5) Give reasons. “Why plastic containers are used as storing devices.”

Ans: – Plastic containers are very light, strong, and durable and plastic can be moulded into different shapes and sizes. Plastic materials will not corrode easily. More over plastics are generally cheaper than metals.

Plastics containers are used as storage devices because it won’t get reacted with the substances which it stores. That why plastics containers are used as storing devices.

Application of concepts

(1) How synthetic fibres have changed our daily life?

Ans: – Synthetic fibres are replaced many natural fibres. Now a day’s people using more synthetic fibres because they are different from natural fibres synthetic fibres absorb less water and dry at a faster rate. Some are even water proof. Most of them are durables expensive readily available, affordable and are easy for maintenances. That is the reasons behind fibres have changed our daily life.

(2) If we make electric switches with thermo plastics. What would happen?

Ans: – Usually electric switches are made up of thermo setting plastic. Thermosetting plastic strengthen during being heating. BUT when electrics switch made up with thermoplastics it can be melted due to heat. But thermosetting plastics can’t melt on heating of electricity.

(3) What could be the consequences? If plastics are not properly disposed.

Ans: – If plastics are not properly disposed it may harm or destroy our environment. Plastic is an non bio-degradable waste and plastics takes several years to decompose in the soil. If it is not properly disosed, then it will cause a lot of land pollution. Sometimes, packed food in plastics bags thrown around anywhere for that it causes for burning process of synthetic material/plastics is also very dangerous because the process of burning releases a lot of poisonous fumes into air causing air pollution.

So it is necessary to have a proper plastics disposal system or it is better to avoid or minimize the used of plastics to keep our environment safe and clean.

(4) Is there any such effort for solid waste management taking place in your village/Town? How do you appreciate 4R principle?

Ans: – Yes, people in villages are being given awareness for not throwing waste anywhere. The dustbins are also provided so that they can keep their area clean. Stop dumping solid waste on any empty plots if someone will do this. They must be punished for this. They also can adopt recover, mechanisms to convert waste into a usables. The 4R principal means



Reuse and


It is a new way to avoid plastics and it is very effective in many areas. This 4R principle is creating a car friendly environment. I heart fully congratulate our govt. And also, supreme court that gave order to implement this in all the cities of India by 2003.

(5) Where do we use the process of recycling? How is it useful? Give examples.

Ans: -The process of recycling is used in various ways like drainage water recycled in clean water, wires, glass, paper etc… Item can be repeatedly reused or recycled.

Recycling reduce the waste on the earth.

The PS(code – 6) used for making coffee cups, egg boxes, packing peanuts and “take out” food packing can be recycled.

Recycling can be used to obtain materials from which the original products were made.

Example: – Paper can be recycled. IT can be crushed. Then the impurities can be removed and fresh new paper can be produced. This will save many wood and forests in the world.

 (6) Rani wants to buy clothes to her parents for winter wear. What types of clothes would you suggest? Specify reasons.

Ans: – I suggest some clothes which keep our body warm during wearing this. The clothes are like – sweaters, shawls, jackets, woollen dress materials etc.

All these are made up of natural wool or fake fun, known as acrylic.

They are best for winter as they trap in air between their trap in air between their fibres and make us feel hot and cozy.

Higher Order Thinking Questions

(1) What made the human beings to search for the alternative for natural fibres?

Ans: – The following reasons are –

(i) Natural fibres getting from are very expensive.

(ii) Generally all these fibre is not affordable and accessible for everyone.

(iii) Maintenance of natural fibre is very difficult.

(iv) Some of natural fibre is not also strong and its takes huge time.

For all these reasons human beings t search for the alternative for natural fibres.

(2) Imagine what would happen if we do not discover plastics?

Ans: – If we do not discover plastics –

(i) Environment will be too cleaned and safe.

(ii) Pollution will be under control.

(iii) Many of animals would eat only grass rather than plastics

(iv) Specially global warming will not be occurring.

If there was no plastics invension then we would have used jute bags, cloths bags, etc… Moreover our life would be simple.

(3) Thermo plastics are eco friendly than thermo setting plastics. Do you agree with statement? Why?

Ans: – Thermo plastics are plastics which will soften when heated and harden when cooled.

 (5) Indiscriminate usage of plastic is a serious threat to bio diversity. What are the efforts of Government and Non government organizations in this regard?

Ans: – The use of plastics has become a part of our life. It is a difficult in modern times to imagine a world without plastics.

Supreme Court gave a judgment on ways and means of solid waste management and gave order to implement this in all the cities of India by 2003. We have to follow the ways.

NGO’s Government and the people flow the 4R principle as Reduce, Recycle, Reuse, Recover.

The principal of recover plays, major in this solid waste management. Solid waste should be converted into resources such as electricity, heat, compact and fuel through thermal and biological means.

Our government should take some steps to protect the environment. It is duty of the government and also the citizen of the world should protect the environment. Municipalities, Gram Panchayats also involves in this process of protect our world from plastics and they should collecting the waste and deemp at one place.

Multiple Choice Questions

(1) Rayon is prepared by

Ans: – (d) cellulose.

(2) Necessity of labels on Clothes

Ans: – (b) to identify fabric content

(3) The material which is not decomposed by natural process is called

Ans: – (a) Non bio- degradable material

(4) The symbol represents

Ans: – (d) Others

(5) Which is a Natural fibre among the following

Ans: – (d) Silk

Updated: August 31, 2020 — 4:17 pm

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