Sulphur dioxide and nitrogen oxides are oxidised to form sulphuric acid and  ?

Which causes brown air in traffic congested city ?

Mixture of smoke and fog is called :

Which is generated during the burning of coal and petroleum products ?

Name the coolant gas used in refrigerators ?

Which radio active substance will cause Leukemia ?

Which is the product of incomplete combustion of fossil fuels in automobiles ?

Which is the unit of sound level ?

Which is called the organ of hearing ?

Bhopal Gas Tragedy was in the year ?