Which of the following statements about carbon monoxide in the air is correct?

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Question

RRB NTPC - 2025

General Science

Which of the following statements about carbon monoxide in the air is correct?

This question was previously asked in

RRB NTPC 2025 Under Graduate CBT 2 Question Paper PDF (17-Sep-2026) (Shift 1)

It is harmless because it is quickly converted into oxygen

The incomplete combustion of fossil fuels produces it and replaces oxygen in haemoglobin

It is released only from natural forest fires and volcanoes

It is less dangerous than carbon dioxide for human health

The correct answer is

The incomplete combustion of fossil fuels produces it and replaces oxygen in haemoglobin

Carbon monoxide, produced by the incomplete combustion of fossil fuels, binds to haemoglobin in place of oxygen, making it dangerous to human health.

It is not harmless, not released only from natural sources, and is actually more dangerous than commonly assumed, not less dangerous than carbon dioxide.

Hence, 'The incomplete combustion of fossil fuels produces it and replaces oxygen in haemoglobin' is the correct answer.

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