Question

Classical smog is

• A. Dark brown smog
• B. Yellow brown smog
• C. Los Angeles smog
• D. Smog with secondary pollutants

Answer 1

The correct option is A Dark brown smog

Smog is the fog containing smoke. Smog is of two types depending upon the type of pollutants; classical smog and photochemical smog.

• Classical smog is formed when there is high concentration of sulphur dioxide and particulate matter produced due to combustion of fuels. It occurs in cold and humid climate. It is also known as London smog or Sulphurous smog and causes dark brownish colour of atmosphere.
• Photochemical smog is formed when sunlight acts on the oxides of nitrogen and hydrocarbons produced from factories or by automobiles. It occurs in warm and dry climate. It is also known as Los Angeles smog and causes light brownish colouration of atmosphere.

So, the correct answer is 'Dark brown smog'.