Question

ASSERTION
Suspended particulate matter (SPM) is an important pollutant released by diesel vehicles.
REASON
Catalytic converters greatly reduce pollution caused by automobiles.
A. Both Assertion and Reason are correct and reason is the correct explanation for Assertion
B. Both Assertion and Reason are correct but reason is not the correct explanation for Assertion.
C. Assertion is correct but Reason is incorrect.
D. Both Assertion and Reason are incorrect

Answer 1

The burning of carbon-containing fuels is responsible for the release of harmful gases and it also leaves behind ash and fine particles. These fine particles are known as suspended particulate matter or SPM. If these matters are not disposed of properly, they may cause huge air and water pollution.

Complete answer:
Suspended particulate matter is also known as atmospheric particulate matter and is a type of microscopic solid or liquid substance that remains suspended in the atmosphere of the earth. These matters are the sum of all solid and liquid particles which are very hazardous. This complex mixture contains both organic and inorganic substances, such as dust, pollen, soot, smoke, and liquid droplets. These particles are too little in size and composition. These microscopic small solid particles or liquid droplets cause air and water pollution. It is also harmful to the respiratory system. The smaller particles can deeply penetrate the breathing system.
Suspended particulate matter or SPM can be defined as particles floating in the air which have a diameter of less than 10μm. SPM may be dispersed through the air due to the burning of carbon fuel processes, various human and industrial activities, or natural sources such as volcanoes or dust storms. As diesel vehicles burn carbon fuel and release the suspended particulate matter, therefore, the assertion is correct.
A catalytic converter is a type of instrument which is mainly used to reduce the number of emissions from automobiles. The current process used in it is a heated metal catalyst to reduce the emissions of carbon monoxide (CO), hydrocarbons, and nitric oxide (NO). All these particles have a contribution to the formation of photochemical smog. In the case of automobile exhaust, the catalytic converter provides a chemical reaction where the burning of unburnt hydrocarbons takes place and leads to a complete combustion. So, the reason is also correct. But this system is not useful in reducing the emission of SPM.

Hence, the correct answer is option (B).

Note: Suspended particulate matter or SPM is a mixture of particles that remain floating in the air. These particles are very small in diameter. They generally come in the air from the burning of biofuel, industry smoke, and various natural resources such as volcanoes. Suspended particulate matter causes air pollution and can cause a severe respiratory problem. A catalytic converter is a type of device which is mainly used to reduce the amount of emissions. A heated metal catalyst is used in this system to reduce the emissions of carbon monoxide (CO), hydrocarbons, and nitric oxide (NO).