UPSC Civil Services Model Paper 8

Bharat stage (BS) emission standards are laid down by the government to regulate the output of air pollutants from the internal combustion engines and spark-ignition engine equipment.
Hence, Statement 1 is correct.
The first emission norms were introduced in India in 1991 for petrol and in 1992 for diesel vehicles.
Hence, Statement 3 is incorrect.
Followed these, the catalytic converter became mandatory for petrol vehicles and unleaded petrol was introduced in the market.
The central government has mandated that vehicle makers must manufacture, sell, and register only BS-VI (BS6) vehicles from April 1,2020.
Hence, Statement 2 is correct.
As per BS-VI emission norms, petrol vehicles will have to effect a 25% reduction in their NOx , or nitrogen oxide emissions .
Diesel engines will have to reduce their HC+NOx ( hydrocarbon + nitrogen oxides ) by 43% , their NOx levels by 68% , and particulate matter levels by 82% .
The emission norms of all models of two-wheelers in India are ahead of Europe (2021) and Japan (2022).
India is the first country to adopt this level of emission norms. (BS-VI norms)