Question

Low visibility during cold weather is due to
(a) formation of fossil fuel
(b) unburnt carbon particles or hydrocarbons suspended in air
(c) lack of adequate power supply
(d) none of these

Answer 1

Smoke fog is a form of extremely polluted air. The term "smog," which is a contraction of the terms "smoke" and "fog," was invented in the early twentieth century to describe smoky fog owing to its opacity and stench. The term was originally meant to allude to pea soup fog, which was a common and significant phenomenon in London from the 19th century until the mid-20th century.

Complete answer:
Because water droplets concentrate in the air during the winter, visibility of developing fog is reduced. The dust particles cling to the drops, reducing vision even further. Smog (smoke + fog) forms as a result of this phenomena, reducing visibility during cold weather seasons. Smog is not only obstructive, but it is also suffocating and hazardous to humans, animals, and plants. Water droplets condense in the air throughout the winter, reducing vision and producing fog. The dust particles cling to the drops, reducing vision even further.
Carbon monoxide (CO), nitrogen oxides (NO and $N{{O}_{2}}$), volatile organic chemicals, and hydrocarbons are the primary culprits from transportation sources (hydrocarbons are the main component of petroleum fuels such as gasoline and diesel fuel). Sulphur dioxides and particulate matter are also emitted by transportation, albeit in considerably lesser quantities than the pollutants listed earlier. The unpleasant vapours, ground level ozone, and particles that make up smog can be formed through a sequence of chemical reactions involving nitrogen oxides and volatile organic compounds, sunlight, heat, ammonia, moisture, and other chemicals.

Hence option b is correct.

Note:
Photochemical smog, which may be seen in cities such as Los Angeles, is a form of air pollution caused by vehicle emissions and industrial pollutants. These pollutants react with sunlight in the atmosphere to produce secondary pollutants, which mix with primary emissions to create photochemical smog. Smog is also exacerbated in other cities, such as Delhi, by stubble burning in nearby agricultural regions. An inversion traps pollutants close to the ground, increasing pollution levels in places such as Los Angeles, Beijing, Delhi, Lahore, Mexico City, Tehran, and others.