UPSC Prelims 2022 · GS Paper I
Question 46: Science and Technology
With reference to polyethylene terephthalate, the use of which is so widespread in our daily lives, consider the following statements :
- 1.Its fibres can be blended with wool and cotton fibres to reinforce their properties.
- 2.Containers made of it can be used to store any alcoholic beverage.
- 3.Bottles made of it can be recycled into other products.
- 4.Articles made of it can be easily disposed of by incineration without causing greenhouse gas emissions.
Which of the statements given above are correct ?
AnswerUPSC’s answer is (a).
Polyethylene terephthalate (PET) is the polyester used in bottles and fabrics. PET fibres are blended with wool and cotton to add strength and crease resistance, and PET bottles are recycled into fibres, sheets and new containers. PET is not suitable for every alcoholic drink, and burning it releases carbon dioxide, a greenhouse gas, along with other pollutants, so statements 2 and 4 are wrong.
- 1. PET fibres are blended with wool and cotton to improve strength.
- 2. PET containers are not suitable for every alcoholic beverage.
- 3. PET bottles can be recycled into other products.
- 4. Incineration of PET releases carbon dioxide and other pollutants.
How you could have got this
- If you were sure statement 1 is correct, (b) and (d) go: each of them leaves 1 out.
What you needed to know: PET fibres are blended with wool and cotton to improve strength.
- Then, if you were sure statement 3 is correct, (c) goes: it leaves 3 out.
What you needed to know: PET bottles can be recycled into other products.
Only (a) is left. You didn’t need statements 2 or 4.
Which options go is worked out from UPSC’s key and the options, not by a model.
Why each option is right or wrong
- (a) Correct. Blending with natural fibres and recycling are both valid.
- (b) Wrong. Statements 2 and 4 are false.
- (c) Wrong. Statement 4 is false: incineration emits greenhouse gases.
- (d) Wrong. Statement 2 is false.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2022, General Studies Paper I, Series A. The paper on upsc.gov.in.