Which of the following gases are NOT released due to incomplete combustion of fuel?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Oxygen and hydrogen
Combustion of fossil fuels, mining and industries are the main sources of air pollution. With the growing use of fuels, more toxic gases go into the air.
Option (1) Oxygen and hydrogen — Not released due to combustion of fuel. Oxygen and hydrogen are not among the substances that the burning of fuels releases.
Option (2) Carbon dioxide and carbon monoxide — Released due to combustion of fuel. Burning fossil fuels releases both carbon dioxide and carbon monoxide.
Option (3) Hydrocarbons and lead — Released due to combustion of fuel. Both hydrocarbons and lead are released into the air by these processes.
Option (4) Carbon monoxide and lead — Released due to combustion of fuel. Carbon monoxide and lead are both released into the air by these processes.
Note: The given answer is as per the official NTA Answer Key. The book does not use the words “incomplete combustion”. It gives the substances that the combustion of fossil fuels releases, and oxygen and hydrogen are not among them.
NCERT (2026-27): “Air Pollution … Combustion of fossil fuels, mining and industries are the main sources of air pollution. These processes release oxides of sulphur and nitrogen, hydrocarbons, carbon dioxide, carbon monoxide, lead and asbestos.” |