Magnetite particles, suspected to cause neurodegenerative problems, are generated as environmental pollutants from which of the following?
- 1. Brakes of motor vehicles
- 2. Engines of motor vehicles
- 3. Microwave stoves within homes
- 4. Power plants
- 5. Telephone lines
Select the correct answer using the code given below.
1, 2, 3 and 5 only
1, 2 and 4 only
3, 4 and 5 only
1, 2, 3, 4 and 5
Answer is Wrong!
Answer is Right!
This question was previously asked in
UPSC IAS – 2021
Let’s examine the potential sources:
1. Brakes of motor vehicles: Brake pads and rotors (often made of cast iron, rich in iron) undergo friction at high temperatures during braking. This process releases wear particles, a significant portion of which are iron oxides, including magnetite. This is a known source of airborne particulate matter in urban environments.
2. Engines of motor vehicles: Internal combustion engines operate at high temperatures, and combustion processes can produce various metal oxides as part of particulate emissions. Friction within the engine can also contribute wear particles. While complex, motor vehicle exhaust is a source of fine metallic particles.
3. Microwave stoves within homes: Microwave ovens heat food using electromagnetic radiation. They do not involve combustion or significant friction/wear in a manner that would generate airborne magnetite particles as an environmental pollutant.
4. Power plants: Combustion of fossil fuels (especially coal and heavy fuel oil) in power plants involves high temperatures and the burning of materials containing trace metals, including iron. Power plants are a significant source of various particulate emissions, including metal oxides like magnetite.
5. Telephone lines: Traditional copper telephone lines are made of copper, not iron. Modern fiber optic cables are made of glass/plastic. Neither involves processes that would generate airborne magnetite particles.
Based on the known sources of magnetite particles from combustion and friction/wear processes, brakes of motor vehicles, engines of motor vehicles, and power plants are plausible sources. Microwave stoves and telephone lines are not.