Singareni Collieries still uses canaries to detect presence of ______ gas.
Fill in the blank with correct option.
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → carbon monoxide
Canaries show distress even when a very small amount of carbon monoxide is in the air, so they warn the miners of this deadly gas.
Note: This question is taken from the pre-rationalised NCERT book. The latest edition (2026-27) does not have this part. An extract of the pre-rationalised NCERT book is given below for the benefit of students.
Pre-rationalised NCERT:
News clipping, India: People and Economy, Chapter 7 (page 78), pre-rationalised book |
