The upper stratosphere,consisting of the ozone layer,protects us from the sun's radiation that falls in the wavelength region of

The pollutants which come directly into the air from sources are called primary pollutants. Primary pollutants are sometimes converted into secondary pollutants. Which of the following belongs to secondary air pollutants?

Which of the following statement$(s)$ is/are incorrect:

$BOD$ stands for

Write a short note on the effect of Global warming and Greenhouse effect on environment.

Mention the components of photochemical smog and its effects.