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Prelims 2013 paper

UPSC CSE Prelims 2013 · GS Paper I · Minerals, energy & industry

With reference to the usefulness of the byproducts of the sugar industry, which of the following…

UPSC Civil Services (Preliminary) Examination 2013, General Studies Paper I — Minerals, energy & industry.

Prelims 2013

Minerals, energy & industry Easy

With reference to the usefulness of the byproducts of the sugar industry, which of the following statements is/are correct?

  1. 1.Bagasse can be used as biomass fuel for the generation of energy.
  2. 2.Molasses can be used as one of the feedstocks for the production of synthetic chemical fertilizers.
  3. 3.Molasses can be used for the production of ethanol.

Select the correct answer using the codes given below:

Answer & explanation

Answer: (c) 1 and 3 only

Bagasse, the fibre left after crushing cane, is burnt as fuel to raise steam and generate power. Molasses is fermented into ethanol. Synthetic chemical fertilisers such as urea are made from fossil feedstocks like natural gas, not molasses. So only statements 1 and 3 are correct.

  • ✓ 1. Sugar mills burn bagasse as boiler fuel to generate steam and electricity. Surplus power from such cogeneration can be supplied to the grid. This makes bagasse a biomass fuel for energy generation.
  • ✗ 2. Synthetic nitrogen fertilisers like urea are made from ammonia, which is produced from fossil feedstocks. In India these are mainly natural gas, with naphtha and fuel oil in some plants. Gas is pooled and supplied to fertiliser plants for urea production. Molasses is not a feedstock for synthetic fertilisers.
  • ✓ 3. Molasses is fermented to give alcohol (ethanol). India's molasses-based distilleries are a major source of ethanol for petrol blending.

Remember · Bagasse gives fuel for steam and power. Molasses gives ethanol. Synthetic fertilisers like urea use natural gas or other fossil feedstocks, not molasses.

📘 Read it in NCERT: Class 10 Science, Ch 4 (practise this chapter)

Sources

Question: UPSC Civil Services (Preliminary) 2013, General Studies Paper I. Explanation: Minimalist IAS, checked 25 Oct 2026 (how we verify). ·

Cite this question: UPSC CSE Prelims 2013 — minimalistias.com/pyqs/prelims/2013/q80

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