Question

Smog that occurs due to low temperature and has reducing environment is
A) Photochemical smog
B) Los Angeles smog
C) Nonsulphurous smog
D) London smog

Answer 1

It is also known as classical smog. Smoke, fog, and sulphur dioxide are the components of this type of smog. Depending on the form of pollutants, smog is of two kinds; classical smog and photochemical smog.

Complete answer:
First we should know about smog to answer this question. Smog is a smoke-containing mist. From the words smoke and fog, the term is derived.
Now, let us find the solution from the options-
The smog which is formed due to high concentration of sulphur dioxide and particulate matter which are generated due to fuel combustion, this type of smog is known as classical smog, also known as London smog or Sulphurous smog, is formed. It happens in cold and humid climates.
Photochemical smog, also known as Los Angeles smog, is created when nitrogen oxides and hydrocarbons generated from factories or vehicles are polluted by sunlight. It occurs in hot and dry conditions and has an oxidising nature. Therefore, the option A and B are incorrect options.
Non sulphurous smog is not a correct option because it is smog which occurs due to low concentration of sulphur dioxide in the atmosphere. Therefore, option C is an incorrect option.
Hence, classical smog or London smog is the smog that exists because of low temperatures, i.e. in cold weather, and has a declining atmosphere.

Thus, the correct answer is option (D) London smog

Note: Photochemical smog is a grayish brown-gray haze formed by the effect of solar UV radiation on the atmosphere polluted with oxides of nitrogen and hydrocarbons. It includes air pollutants that are anthropogenic, primarily nitric acid, ozone, and organic compounds that are captured by temperature inversion near the ground. Such pollutants, as well as some others, can affect human health and cause plant damage. Whereas classical smog is mainly caused due to high concentration of sulphur dioxide.